ORIGINAL RESEARCH article

Front. Virol., 03 June 2026

Sec. Emerging and Reemerging Viruses

Volume 6 - 2026 | https://doi.org/10.3389/fviro.2026.1805695

Prevalence of pre-diabetes, newly diagnosed diabetes, and associated COVID-19 disease severity in patients hospitalized at Sir Ketumile Masire Teaching Hospital, Botswana

  • 1. Department of Internal Medicine, Faculty of Medicine and Health Sciences, University of Botswana, Gaborone, Botswana

  • 2. Botswana Harvard Health Partnership, Gaborone, Botswana

  • 3. Department of Pathology, Division of Medical Virology, Stellenbosch University, Cape Town/Pretoria, South Africa

  • 4. Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, United States

  • 5. School of Allied Health Sciences, University of Botswana, Faculty of Medicine and Health Sciences, Gaborone, Botswana

  • 6. School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa

  • 7. Department of Internal Medicine, Princess Marina Hospital, Gaborone, Botswana

  • 8. Department of Oncology, Centre Hospitalier Univeritaire (CHU) Brugmann Hospital, Vrije Universiteit Brussel, Brussel, Belgium

Abstract

Background:

The mechanism of diabetes with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and onset in COVID-19 patients remains unclear. We aimed to determine the prevalence of pre-diabetes and newly diagnosed diabetes, and to assess their association with COVID-19 disease severity in patients admitted to Sir Ketumile Masire Teaching Hospital (SKMTH), Botswana.

Methods:

We conducted a single-center, retrospective cross-sectional study at SKMTH. A random sample of 100 adult patient records was reviewed from 992 eligible admissions with laboratory-confirmed COVID-19 between June 2020 and June 2021. Patients with a known history of diabetes were excluded. Participants were classified as normoglycemic, pre-diabetic, or newly diagnosed diabetic based on their first available laboratory results, primarily HbA1c, during admission. Univariate and multivariable Poisson regression was used to identify factors associated with severe COVID-19 disease and mortality.

Results:

Among 100 patients, 73% were male, with a mean age of 49.5 years (Standard deviation 13.7). Hypertension (34%) and HIV infection (24%) were the most prevalent comorbidities. Pre-diabetes was detected in 35% (95%CI:25.7–45.2) and newly diagnosed diabetes in 43% (95% CI: 33.1–53.6) of participants. Having diabetes increased the risk of severe COVID-19 [adjusted Relative Risk (aRR)=5.74; 95%CI:1.31–25.2, p=0.02]. Sepsis was also an independent predictor (aRR=5.90; 95% CI:1.83–18.7, p=0.003). In contrast, male sex was associated with a reduced risk of severe disease compared with females (aRR=0.40; 95% CI:0.16–1.0, p=0.05). HIV, hypertension, and alcohol use were not significantly associated with severe disease. Residing in rural areas was associated with a reduced risk of severe disease (aRR=0.41; 95%CI:0.15-1.10). Of the 98 participants with available outcome data, 44 (44.9%) died during hospitalization, and 54 (55.1%) were discharged alive. Newly diagnosed diabetes was associated with increased in-hospital mortality in both univariable (RR = 3.45, 95% CI: 1.17–10.21; p=0.025) and multivariable analyses (aRR=3.71, 95%CI:1.49–9.26; p=0.005).

Conclusion:

There was a high burden of previously undiagnosed pre-diabetes and diabetes among COVID-19 inpatients in Botswana. Among hospitalized COVID-19 patients without previously known diabetes, newly diagnosed diabetes was associated with a higher risk of severe disease and poor in-hospital outcomes, highlighting the importance of integrating routine diabetes screening into COVID-19 care pathways.

1 Introduction

The coronavirus disease 2019 (COVID-19), caused by the novel SARS-CoV-2 virus, was declared a global pandemic by the WHO on March 11, 2020 (). The pandemic resulted in over 765 million confirmed cases and more than 6.9 million deaths worldwide (). The disease predominantly affects the respiratory tract, with severity ranging from asymptomatic or mild to severe or critical illness (, ). A key observation throughout the pandemic has been the increased morbidity and mortality in vulnerable populations, particularly among the elderly and individuals with pre-existing comorbid conditions, including diabetes (, ). Various studies show an increased severity of the COVID-19 disease in the diabetic population ().

Diabetes mellitus is a disorder of glucose metabolism that is a leading cause of morbidity and mortality, often attributed to cardiovascular diseases (). It is also the leading cause of end-stage renal disease, adult-onset blindness, and non-traumatic lower extremity amputations (). Diabetes is one of the fastest-growing global health emergencies of the 21st century. The International Diabetes Federation estimates that approximately 473 million people were living with diabetes in 2019, with figures projected to rise to 700 million by 2045 (). Three-quarters (75%) of those with diabetes were living in low- and middle-income countries (). The diabetic population had a disproportionate burden of the COVID-19 disease, as studies have shown a strong association between diabetes and worse outcomes ().

The precise mechanisms linking COVID-19 and diabetes are still under investigation, but several hypotheses have been proposed (). The SARS-CoV-2 virus, like its predecessor Middle East Respiratory Syndrome (MERS), uses its spike glycoprotein for binding to host angiotensin-converting enzyme 2 (ACE2) for cell entry (). These receptors are highly expressed not only in the lungs but also in various other organs, including the pancreas, liver, and adipose tissue. Viral binding to pancreatic beta-cells may directly impair insulin production. Furthermore, the intense inflammatory response triggered by the infection, known as a “cytokine storm”, can induce significant insulin resistance and cellular damage, leading to severe hyperglycemia (, ). These acute effects may exacerbate pre-existing low-grade inflammation and metabolic dysregulation common in diabetes, leading to worse outcomes. However, our study did not measure pancreatic function and cannot distinguish these mechanisms.

While the association between established diabetes and severe COVID-19 is well documented (, ). Although reports from other sub-Saharan African countries, including South Africa (, ), Nigeria (), and Kenya (), had begun to describe the relationship between diabetes and COVID-19 outcomes, fewer studies had examined the prevalence of previously undiagnosed pre-diabetes and diabetes among hospitalized patients in this region (), and on how these glucose abnormalities relate to disease severity.

We therefore undertook this study to address this gap in Botswana and to contribute to the emerging sub-Saharan African evidence base. We determined the prevalence of pre-diabetes and newly diagnosed diabetes and factors associated with COVID-19 disease severity and in-hospital mortality among this cohort.

2 Methods

2.1 Study design and setting

We conducted a single-center, retrospective cross-sectional study at Sir Ketumile Masire Teaching Hospital (SKMTH) in Gaborone, Botswana. SKMTH was designated as the primary COVID-19 isolation and management hospital at the time of the study. The study period was from June 2020 to June 2021, during which 1,832 patients were admitted with confirmed SARS-CoV-2 infection.

2.2 Study population and sampling

The study population included all adult patients (age ≥18 years) admitted to SKMTH with a laboratory-confirmed SARS-CoV-2 positive test. Patients with a known history of diabetes mellitus, pregnant patients, and those with incomplete medical records were excluded. A total of 992 files met the inclusion criteria. From this eligible population, a simple random sampling technique was used to select 100 patient files for review. At the time of study planning, no Botswana-specific prevalence was available, and our sample size was based on the available regional prevalence estimate of pre-diabetes from Uganda. This calculation was intended primarily to support the estimation of the prevalence of dysglycemia in the study population. Analyses of associations with clinical outcomes were therefore considered exploratory ().

2.3 Data collection

A standardized data abstraction sheet was used to collect epidemiological, clinical, laboratory, treatment, and outcome data from patient records. Patient information such as age, sex, marital status, employment, location of residence, and comorbidities (e.g., hypertension, HIV, sepsis, asthma) was collected. Laboratory data included standard blood counts, renal and liver function tests, creatinine kinase, and, most importantly, HbA1c, random blood sugar (RBS), and fasting blood sugars (FBS). Oxygenation requirements were used to classify disease severity as mild (low-flow oxygen), moderate (CPAP/high-flow oxygen), or severe (invasive mechanical ventilation).

2.4 Classification of glucose abnormality

Participants were classified into three categories: normal glucose (HbA1c <5.7% or FBS <5.6 mmol/L), pre-diabetes (HbA1c between 5.7% and 6.4%, or FBS between 5.6-6.9 mmol/L), and newly diagnosed diabetes (HbA1c ≥6.5% or FBS ≥7.0 mmol/L, or RBS ≥11.1 mmol/L with symptoms of diabetes). The primary criterion for classification was the first available HbA1c measurement upon admission. In cases where HbA1c was missing or not ordered, classification was based on random or fasting blood glucose levels. Missing data were not imputed. Analyses were conducted using available-case denominators for each variable and complete-case data for each model. Denominators are shown in the tables.

2.5 Statistical analysis

Data were captured in REDCap and exported to STATA and R for analysis. Descriptive statistics were used to summarize participant characteristics, with proportions estimated with 95% confidence intervals using binomial exact methods. Univariate and multivariate Poisson regression with robust standard errors were performed to determine factors associated with severe disease and mortality. Variables with a p-value of <0.2 in the univariate analysis were included in the multivariate model. Where simultaneous inclusion of screened categorical variables resulted in sparse-cell instability or quasi-complete separation, the more stable specification was retained. We also conducted an HbA1c-restricted sensitivity analysis. A p-value of <0.05 was considered statistically significant.

2.6 Ethical considerations

The study was conducted in accordance with the Helsinki Declaration. This study was approved by the University of Botswana Institutional Review Board (UBR/RES/IRB/GRAD/299), the Ministry of Health (HPRD: 6/14/1), and the SKMTH ethics committee (SKMTH 01/14). Individual informed consent was waived due to the retrospective nature of the study, which used anonymous clinical data. Patient confidentiality was protected by assigning subjects case study numbers, and no personally identifiable information was entered into the database.

3 Results

3.1 Participant characteristics and comorbidities

A total of 100 patient files were reviewed, all of whom were adults aged 18 years or older (Table 1). The mean age was 49.5 years (SD 13.7), with 63% of participants falling in the 36–60-year age category. The majority of the cohort was male (73%). Most participants were of African descent (98%) and resided in urban areas (79%). The most prevalent comorbid conditions were hypertension (34%) and HIV (24%). Most participants (57%) received steroids during their hospital stay (Figure 1).

Table 1

Characteristics / N = 100No. of patientsPercent
Age category (years)
  Mean (Standard Deviation)49.5 (13.7)
  18–35 years1818
  36–60 years6363
  >60 years1919
Sex
  Males7373
  Females2727
Race
  African9898
  Non-African22
Marital status
  Single2626
  Married5050
  Widow/Widower22
  Unknown2222
Location of residence, n =99
  Rural2121
  Urban7879
Employment status, n =100
  Formally employed4343
  Self-employed2323
  Unemployed3333

Socio-demographic and clinical characteristics of the study participants (N = 100).

Figure 1

3.2 Prevalence of pre-diabetes and diabetes

Pre-diabetes was detected in 35% (95% CI: 25.7–45.2) and newly diagnosed diabetes in 43% (95% CI: 33.1–53.6) of participants. Only 22% of participants had normal glucose levels and normal HbA1c. A total of 84 (84%) participants had HbA1c values available, while 16 were classified based on fasting or random glucose alone. Pre-diabetes and newly diagnosed diabetes were common in the cohort. Because glucose values obtained during acute illness may reflect transient stress hyperglycemia, a sensitivity analysis was performed, restricting the definition of glycemic status to participants with available HbA1c measurements.

3.3 Risk factors for COVID-19 disease severity and mortality

COVID-19 severity was categorized as mild (50%), moderate (32%), or severe (18%). Univariate and multivariate Poisson regression analyses were performed to identify risk factors for severe disease (Table 2a). In the adjusted analysis, newly diagnosed diabetes was associated with severe COVID-19 (aRR=5.74; 95% CI: 1.31-25.2, p=0.02); however, the confidence interval remained wide, indicating limited precision.

Table 2a

PredictorN (%)Univariate RR
(95% CI)
P-valueAdjusted RR
(95% CI)
P-value adj
Diabetic
 Normal22/100 (22.0)ReferenceReference
 Pre-diabetic35/100 (35.0)2.51 (0.30-21.06)0.3951.95 (0.33-11.50)0.461
 Diabetic43/100 (43.0)6.65 (0.93-47.60)0.0595.74 (1.31-25.15)0.02
Age
 Age (per year)100 (100.0)1.01 (0.98-1.04)0.696
Sex
 Female27/100 (27.0)ReferenceReference
 Male73/100 (73.0)0.30 (0.13-0.67)0.0040.40 (0.16-1.01)0.052
Marital status
 Single26/78 (33.3)Reference
 Married52/78 (66.7)0.40 (0.12-1.37)0.143
Employment
 Unemployed33/99 (33.3)ReferenceReference
 Self-employed23/99 (23.2)0.32 (0.08-1.34)0.1190.15 (0.01-1.55)0.111
 Employed43/99 (43.4)0.60 (0.25-1.44)0.2491.36 (0.50-3.66)0.548
Residence
 Rural21/99 (21.2)ReferenceReference
 Urban78/99 (78.8)0.49 (0.21-1.18)0.1120.41 (0.15-1.10)0.075
Hypertension
 No66/100 (66.0)Reference
 Yes34/100 (34.0)1.55 (0.68-3.57)0.3
HIV
 No39/63 (61.9)Reference
 Yes24/63 (38.1)1.39 (0.53-3.65)0.501
Sepsis
 No86/97 (88.7)ReferenceReference
 Yes11/97 (11.3)2.61 (1.02-6.68)0.0465.86 (1.83-18.74)0.003

Poisson regression table with factors associated with COVID-19 disease severity using a combined glycemic definition.

Multivariable severity model retained predictors with univariable p < 0.20 and forced inclusion of diabetes. Marital status met the screening criterion in the severity analyses but was omitted from the adjusted model because inclusion with employment status created sparse-cell instability and quasi-complete separation.

Males had a reduced risk for severe COVID-19 compared to females (aRR=0.40; 95% CI: 0.16-1.0, P = 0.05). Having sepsis was also strongly associated with a 5.9 times increased risk for severe disease (aRR=5.9; 95% CI: 1.83-18.7, P = 0.003). HIV, hypertension, and alcohol use were not significantly associated with severe disease. In the HbA1c-restricted sensitivity analysis (Table 2b), the association between newly diagnosed diabetes and severe COVID-19 was attenuated compared with the main analysis, and the confidence intervals were wider, indicating reduced precision, but still statistically significant (aRR= 3.93; 95% CI:1.14-13.57. p=0.03). These findings suggest that part of the dysglycemia observed in the full cohort may have been influenced by classification based solely on admission glucose values.

Table 2b

PredictorN (%)Univariate RR
(95% CI)
P-valueAdjusted RR
(95% CI)
P-value adj
Diabetic
(HbA1c-restricted)
 Normal19/84 (22.6)ReferenceReference
 Pre-diabetic31/84 (36.9)1.84 (0.21-16.43)0.5860.93 (0.11-8.08)0.945
 Diabetic34/84 (40.5)5.59 (0.77-40.37)0.0883.93 (1.14-13.57)0.03
Age
 Age (per year)84 (100.0)1.01 (0.98-1.04)0.616
Sex
 Female21/84 (25.0)ReferenceReference
 Male63/84 (75.0)0.19 (0.07-0.49)<0.0010.18 (0.04-0.70)0.014
Marital status
 Single24/67 (35.8)Reference
 Married43/67 (64.2)0.22 (0.05-1.06)0.060
Employment
 Unemployed27/83 (32.5)ReferenceReference
 Self-employed18/83 (21.7)0.43 (0.10-1.83)0.2530.21 (0.02-2.47)0.213
 Employed38/83 (45.8)0.51 (0.18-1.43)0.2002.70 (0.69-10.56)0.153
Residence
 Rural19/83 (22.9)ReferenceReference
 Urban64/83 (77.1)0.47 (0.18-1.28)0.1420.33 (0.11-1.03)0.057
Hypertension
 No56/84 (66.7)Reference
 Yes28/84 (33.3)1.50 (0.58-3.90)0.406
HIV
 No35/55 (63.6)Reference
 Yes20/55 (36.4)1.46 (0.51-4.18)0.482
Sepsis
 No72/81 (88.9)ReferenceReference
 Yes9/81 (11.1)4.00 (1.50-10.66)0.0067.54 (1.69-33.63)0.008

Poisson regression table with factors associated with COVID-19 disease severity using an HbA1c-restricted sensitivity analysis.

Multivariable severity model retained predictors with univariable p < 0.20 and forced inclusion of diabetes. Marital status met the screening criterion in the severity analyses but was omitted from the adjusted model because inclusion with employment status created sparse-cell instability and quasi-complete separation.

Of the 98 participants with available outcome data, 44 (44.9%) died during hospitalization and 54 (55.1%) were discharged alive. In the full cohort (Table 3a), newly diagnosed diabetes was associated with increased in-hospital mortality in univariable analysis (RR 2.36, 95% CI: 1.15–4.84; p=0.019), but this association did not persist after adjustment (aRR 1.97, 95% CI: 0.91–4.25; p=0.085). Male sex remained associated with lower mortality, while HIV, severe COVID-19, and sepsis were not independently associated with mortality in the adjusted model. Remdesivir use remained strongly associated with mortality.

Table 3a

PredictorN (%)Univariate RR
(95% CI)
P-valueAdjusted RR
(95% CI)
P-value adj
Diabetic
 Normal22/100 (22.0)ReferenceReference
 Pre-diabetic35/100 (35.0)1.19 (0.51-2.74)0.6890.85 (0.43-1.64)0.621
 Diabetic43/100 (43.0)2.36 (1.15-4.84)0.0191.36 (0.57-3.24)0.492
Age
 Age (per year)100 (100.0)1.02 (1.00-1.03)0.0171.01 (0.99-1.03)0.201
Sex
 Female27/100 (27.0)ReferenceReference
 Male73/100 (73.0)0.36 (0.25-0.53)<0.0010.48 (0.30-0.76)0.002
Marital status
 Single26/78 (33.3)Reference
 Married52/78 (66.7)1.26 (0.65-2.44)0.490
Employment
 Unemployed33/99 (33.3)ReferenceReference
 Self-employed23/99 (23.2)0.93 (0.56-1.52)0.7660.83 (0.41-1.68)0.612
 Employed43/99 (43.4)0.55 (0.32-0.95)0.0320.38 (0.20-0.70)0.002
Residence
 Rural21/99 (21.2)Reference
 Urban78/99 (78.8)0.86 (0.52-1.43)0.552
Hypertension
 No66/100 (66.0)Reference
 Yes34/100 (34.0)1.13 (0.72-1.76)0.606
HIV
 No39/63 (61.9)ReferenceReference
 Yes24/63 (38.1)1.58 (0.86-2.93)0.1442.06 (1.16-3.68)0.014
Severity
 No82/100 (82.0)ReferenceReference
 Yes18/100 (18.0)2.46 (1.76-3.46)<0.0011.34 (0.74-2.45)0.334
Asthma
 No88/99 (88.9)Reference
 Yes11/99 (11.1)1.27 (0.70-2.29)0.432
Remdesivir use
 No58/100 (58.0)ReferenceReference
 Yes42/100 (42.0)10.84 (4.68-25.12)<0.0019.48 (4.29-20.95)<0.001
Sepsis
 No86/97 (88.7)ReferenceReference
 Yes11/97 (11.3)1.50 (0.90-2.50)0.1180.49 (0.26-0.93)0.029

Univariate multivariate analysis of risk factors of in-hospital mortality using a combined glycemic definition.

The multivariable mortality model retained predictors with univariable p < 0.20 and forced inclusion of diabetes. Estimates for remdesivir should be interpreted cautiously because they are likely confounded by indication.

In the HbA1c-restricted sensitivity analysis (Table 3b), newly diagnosed diabetes was associated with increased in-hospital mortality in both univariable (RR = 3.45, 95% CI: 1.17–10.21; p=0.025) and multivariable analyses (aRR=3.71, 95% CI: 1.49–9.26; p=0.005). Male sex remained associated with lower mortality, and HIV infection was independently associated with mortality. Severe COVID-19 and sepsis were not independently associated with mortality after adjustment, while remdesivir use remained strongly associated with mortality.

Table 3b

PredictorN (%)Univariate RR
(95% CI)
P-valueAdjusted RR
(95% CI)
P-value adj
Diabetic
(HbA1c-restricted)
 Normal19/84 (22.6)ReferenceReference
 Pre-diabetic31/84 (36.9)1.48 (0.43-5.03)0.5320.96 (0.36-2.59)0.939
 Diabetic34/84 (40.5)3.45 (1.17-10.21)0.0251.86 (0.64-5.36)0.253
Age
 Age (per year)84 (100.0)1.02 (1.00-1.04)0.0311.02 (0.99-1.05)0.194
Sex
 Female21/84 (25.0)ReferenceReference
 Male63/84 (75.0)0.24 (0.14-0.42)<0.0010.38 (0.21-0.68)0.001
Marital status
 Single24/67 (35.8)Reference
 Married43/67 (64.2)1.07 (0.46-2.48)0.875
Employment
 Unemployed27/83 (32.5)ReferenceReference
 Self-employed18/83 (21.7)0.84 (0.41-1.72)0.6380.87 (0.42-1.79)0.705
 Employed38/83 (45.8)0.47 (0.22-0.98)0.0450.21 (0.11-0.40)<0.001
Residence
 Rural19/83 (22.9)Reference
 Urban64/83 (77.1)0.68 (0.36-1.29)0.234
Hypertension
 No56/84 (66.7)Reference
 Yes28/84 (33.3)1.13 (0.61-2.11)0.696
HIV
 No35/55 (63.6)ReferenceReference
 Yes20/55 (36.4)1.70 (0.76-3.82)0.1994.26 (2.00-9.05)<0.001
Severity
 No70/84 (83.3)ReferenceReference
 Yes14/84 (16.7)3.43 (2.14-5.51)<0.0012.22 (1.09-4.53)0.029
Asthma
 No76/83 (91.6)Reference
 Yes7/83 (8.4)0.85 (0.25-2.85)0.787
Remdesivir use
 No58/84 (69.0)ReferenceReference
 Yes26/84 (31.0)10.49 (4.50-24.42)<0.00111.60 (5.84-23.06)<0.001
Sepsis
 No72/81 (88.9)ReferenceReference
 Yes9/81 (11.1)1.79 (0.91-3.54)0.0920.28 (0.12-0.64)0.002

Univariate multivariate analysis of risk factors of in-hospital mortality using a HbA1c-restricted sensitivity analysis.

Multivariable mortality model retained predictors with univariable p < 0.20 and forced inclusion of diabetes. Estimates for remdesivir should be interpreted cautiously because they likely reflect confounding by indication.

4 Discussion

This retrospective study provides crucial insights into the clinical characteristics and outcomes of COVID-19 in patients with previously undiagnosed glucose abnormalities in Botswana. We found a significantly high prevalence of both newly diagnosed diabetes (43%) and pre-diabetes (35%) among our cohort. These combined figures (78%) are higher than those found in other countries, such as China, where a 2017 national survey found a diabetes prevalence of 12.8% (). The high prevalence in our cohort could be attributed to several factors, including the mean age of 50 years (a high-risk group for developing type 2 diabetes) and the significant oxidative stress and tissue inflammation induced by the SARS-CoV-2 infection.

Our study provides strong evidence that newly diagnosed diabetes is a significant risk factor for severe COVID-19 disease. The adjusted relative risk of 5.74 for severe disease in diabetic patients is consistent with a study by Yi et al. (), which also found that severe cases were more common in diabetic patients. The strong association between sepsis and severe disease (aRR=5.9) may reflect the overlap between the two conditions, as the SARS-CoV-2-induced cytokine storm can mimic sepsis and lead to similar outcomes.

An unexpected finding was the reduced risk for severe COVID-19 in males compared to females (aRR=0.40). This contradicts some international studies, such as one by Grasselli et al. in Italy, who found lower survival rates for older men (). The difference could be due to the disproportionate number of males in our study (73%) or differences in comorbidities and age distribution between the cohorts. For mortality, the association with newly diagnosed diabetes was sensitive to the classification method. It was attenuated and no longer statistically significant in the full cohort after adjustment, but remained significant in the HbA1c-restricted sensitivity analysis. This suggests that the relationship between dysglycemia and mortality should be interpreted cautiously and may be influenced by both classification approach and limited sample size.

The significant association between Remdesivir use and mortality (aRR=9.48) should be interpreted with caution as Remdesivir was part of the standard treatment protocol for severe COVID-19 cases, this finding likely reflects confounding by indication, where sicker patients were more likely to receive the drug and, consequently, have a higher mortality rate, in contrast to other studies that showed a beneficial effects for Remdesivir used reducing the time to recovery of hospitalized patients who require supplemental oxygen and resulting in reduction in mortality and favorable safety profiles (, ). Similarly, corticosteroid use in 57% of participants could have affected blood sugar levels, although their short-term use and the preference for HbA1c in our study likely minimized this effect.

Our findings should be interpreted in the context of emerging African literature showing that diabetes is an important comorbidity in COVID-19. In South Africa, Dave et al. () reported that people living with diabetes had substantially higher risks of hospitalization and death from COVID-19 in a large virtual cohort from the Western Cape. Similarly, multicenter hospital data from Kenya showed that comorbid conditions, including diabetes, were common among admitted patients and contributed to poor outcomes (). Broader African data from critical care settings have also shown high mortality among severely ill patients with COVID-19 and have highlighted the contribution of non-communicable comorbidity to poor prognosis (). However, most of these studies focused on patients with established comorbid disease, whereas our study specifically excluded patients with known diabetes and therefore examined the burden of previously unrecognized dysglycemia detected during admission. In this regard, our study adds Botswana-specific evidence and suggests that a substantial proportion of hospitalized patients with COVID-19 may have unrecognized metabolic dysfunction that only becomes apparent during acute illness.

The high prevalence of undiagnosed glucose abnormalities highlights a critical public health issue in Botswana. Many individuals may be living with pre-diabetes or diabetes without their knowledge, and the COVID-19 pandemic may have served as a wake-up call for these patients and the healthcare system. These findings underscore the importance of integrating routine glucose screening (e.g., HbA1c) into the care of all patients presenting with COVID-19. Early detection and management can mitigate long-term complications and improve quality of life. An important methodological consideration is that not all participants had HbA1c available at admission. Although HbA1c was available for most participants (84%), 16% were classified using fasting or random blood glucose values only. In the context of acute COVID-19 illness, corticosteroid exposure, and physiological stress, these glucose-based measures may reflect transient stress hyperglycemia rather than underlying chronic dysglycemia. To address this, we performed an HbA1c-restricted sensitivity analysis. In that analysis, the association between newly diagnosed diabetes and severe COVID-19 was attenuated but remained statistically significant, albeit with wider confidence intervals, suggesting that some of the dysglycemia identified in the primary analysis may have reflected acute illness-related hyperglycemia.

We observed a relatively high in-hospital mortality compared with the proportion classified as having severe COVID-19 suggests that the oxygenation-based severity definition may not have fully captured the overall burden of critical illness in this cohort. Severity was retrospectively classified based on oxygenation requirements documented in the clinical records, which may have underestimated true disease severity in some patients. For example, patients managed with CPAP or in high-care settings may have remained classified as moderate despite substantial clinical instability. In addition, mortality may have been influenced by complications such as pulmonary embolism, sepsis, and other forms of organ dysfunction, including renal impairment, which were not fully captured by the study variables. Because these complications were not systematically recorded, their contribution to mortality could not be formally evaluated in this analysis.

This study has several limitations. The participants with previously known diabetes were excluded to allow focused assessment of pre-diabetes and newly diagnosed diabetes. Consequently, the study cohort is not representative of all hospitalized COVID-19 patients, and the findings should be interpreted as specific to individuals without established diabetes at admission. There is a possibility of selection bias due to the study’s retrospective design and the availability of patient files with complete data. The American Diabetes Association (ADA) recommends a repeat test to confirm a diabetes diagnosis in asymptomatic individuals, which was not feasible in this study. Because participants with previously known diabetes were excluded by design, our findings apply specifically to patients with newly identified dysglycemia and should not be extrapolated to the entire hospitalized COVID-19 population. The study did not also account for the differences in specific COVID-19 variants circulating at the time, which may have unique clinical and biochemical manifestations. Lastly, although this study provides baseline data, the modest sample size and single-center study may limit the generalizability of these findings. However, as noted, SKMTH was the main isolation center at the peak of the pandemic in Botswana.

5 Conclusion

In conclusion, our study provides a primary and comprehensive description of clinical features of COVID-19 in patients with normoglycemia, pre-diabetes, and newly diagnosed diabetes. The prevalence of both pre-diabetes and diabetes is very high in our community, and diabetes is associated with increased COVID-19 disease severity and mortality. The new onset of diabetes in relation to COVID-19 provides an opportunity to observe these patients long-term. We recommend that all healthcare practitioners closely monitor glucose values for patients presenting with COVID-19 and initiate early treatment. Long-term follow-up for patients with new-onset hyperglycemia is also urgently needed, in line with regional findings that up to 73% of diabetes cases in Africa remain undiagnosed. Future studies need to follow up with these patients to determine whether the glucose derangements are temporary or permanent.

Statements

Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Ethics statement

The studies involving humans were approved by University of Botswana Ethics Committee and Sir Ketumile Masire Teaching Hospital Ethics Committee as well as Human Resource Development Council of Botswana. The studies were conducted in accordance with the local legislation and institutional requirements. The ethics committee/institutional review board waived the requirement of written informed consent for participation from the participants or the participants’ legal guardians/next of kin.

Author contributions

KB: Formal analysis, Resources, Funding acquisition, Writing – original draft, Methodology, Conceptualization, Investigation, Writing – review & editing. SM: Writing – review & editing, Conceptualization, Validation, Methodology, Formal analysis, Supervision, Visualization, Software. GM: Formal analysis, Validation, Data curation, Software, Writing – review & editing, Conceptualization. LB: Data curation, Formal analysis, Validation, Writing – review & editing, Conceptualization. EB: Conceptualization, Writing – original draft, Data curation, Formal analysis, Validation, Project administration, Supervision, Methodology, Writing – review & editing. PV: Methodology, Validation, Data curation, Conceptualization, Supervision, Writing – review & editing, Writing – original draft. TG: Data curation, Formal analysis, Methodology, Conceptualization, Writing – original draft, Validation, Writing – review & editing, Supervision.

Funding

The author(s) declared that financial support was received for this work and/or its publication. The study was supported by the University of Botswana. SM was partially supported by the Fogarty International Center at the US National Institutes of Health (K43TW 012350). Funders had no role in the design, conduct and decision to publish the findings of this study.

Conflict of interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The handling editor BCF declared a shared affiliation with the author SM at the time of review.

Generative AI statement

The author(s) declared that generative AI was not used in the creation of this manuscript.

Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

Summary

Keywords

Botswana, diabetes, dysglycemia, pre-diabetes, SARS-CoV-2

Citation

Bakgethisi K, Moyo S, Mulenga G, Bhebhe LN, Botsile E, Vuylsteke P and Gaolatlhe T (2026) Prevalence of pre-diabetes, newly diagnosed diabetes, and associated COVID-19 disease severity in patients hospitalized at Sir Ketumile Masire Teaching Hospital, Botswana. Front. Virol. 6:1805695. doi: 10.3389/fviro.2026.1805695

Received

06 February 2026

Revised

21 April 2026

Accepted

08 May 2026

Published

03 June 2026

Volume

6 - 2026

Edited by

Burtram Clinton Fielding, Stellenbosch University, South Africa

Reviewed by

Mohammed Rohaim, Cairo University, Egypt

Danzil Eugene Joseph, Stellenbosch University, South Africa

Updates

Copyright

*Correspondence: Tendani Gaolatlhe,

†These authors have contributed equally to this work

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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