Most deaths from non-communicable diseases (NCDs) occur in lower resourced countries (>85%) (1). In the lower-middle-income island of Central Africa, Sao Tome and Principe, 55% of people died from NCDs in 2016 (2). Cardiovascular disease, diabetes, cancer, and respiratory disease, account for more than 80% of NCD premature deaths (1). In the general population of Sao Tome and Principe, 20% had high blood pressure and 6% hypoglycaemia (2). The ill-healthy diet, tobacco, alcohol consumption and low physical activity increase the risk of death from NCDs (1). In Sao Tome and Principe, 7% of adults engaged in harmful alcohol use and 15% were physically inactive (2). Among recent mothers in Sao Tome and Principe, more than 30% were overweight or obese (3). As the number of NCDs grows rapidly in the sub-Saharan region of Africa, including in Sao Tome and Principe (4), due to multiple factors, such as the adoption of an unhealthy lifestyle, and the increase in the average life expectancy of the population (4), it is important to understand the local factors affecting NCDs to monitor changes in burden, measure the progress of the NCD programme, and plan new activities (5). In this regard, data from national communities on single and multiple risk factors for NCDs among adults in Sao Tome and Principe are needed in planning health programmes.

In another island country in Africa in Comoros, among adults (25–64 years) the prevalence of diabetes was 8.5% (6), and overweight and obesity was 28.6 and 22.2%, respectively (7). In other African countries, for example, in Malawi, 16.5% had 3–7 risk factors of NCD (ranging from 5.6% raised blood glucose to 32.9% raised blood pressure) (8), and in Zambia, 26.7% had 3–10 risk factors of NCD (ranging from 6.2% diabetes to 90.4% insufficient fruit and vegetable intake = IFVI) (9).

Social and demographic factors associated with NCD risk factors include older age (10–13), male sex (10, 14), educational level (10, 14), and residing in urban areas (13, 14). The aim of the investigation was to estimate the prevalence and sociodemographic factors associated with seven risk factors of NCDs in adults from 2008 to 2019 in Sao Tome and Principe.

Secondary data from two cross-sectional STEPS surveys conducted in 2008 and 2019 in Sao Tome and Principe were analyzed, with a total response rate of 95.5% in 2008 and 91.5 percent in 2019 (15). Multi-step stratified sampling was conducted to select one person at random of the target age (25–64 years in 2008, and 18–69 years in 2019; the 2019 survey was restricted to 25–64 years for this analysis) per household (15).

SaoTome and Principe has a population of 228,000 in 2022 (16), a literacy rate of 92.8%, an urbanization rate of 76.4% (17), a gross domestic product (GDP) per capita in 2019 of $ 1961; the life expectancy (at birth) increased from 63.5 years in 2000 to 70.4 years in 2019 (18). The NCD programme in Sao Tome and Principe includes implementing the NCD programme and promotion of healthy lifestyles (19). Regarding integration of the NCD programme into primary health care (PHC) in Sao Tome and Principe, partial implementation includes having NCD guidelines, generally available medicine, generally available technologies, and drug therapy at PHC, and not implemented a national list of essential medicines and technology (20), and adhering to the WHO Package of Essential NCDs (PEN) interventions (21). Acccording to the WHO NCD monitor (22), there is poor implementation of NCD reduction measures, including unhealthy diet, tobacco demand and harmful use of alcohol, and public education and awareness campaigns on physical activity.

Study approval was provide by the Ministry of Health Ethical Committee, Sao Tome and Principe, and participants gave written informed consent (15). The data collection followed the WHO’s three STEPS methodology: the first step included the administration of questionnaires (social epidemiology, medical history, use of medicines and health risk behaviour); the second step involved body weight, height and blood pressure measurements; and the third step included biochemical tests (glucose and blood lipids) (23).

The study showed that having 3–7 NCD risk factors among male but not female adults significantly decreased from 36.6% in 2008 to 26.8% in 2019 in Sao Tome and Principe. Some of this reduction may be attributed to strengthened implementation of NCD programme in Sao Tome and Principe (19). Having overweight/obesity and low physical activity significantly increased, and IFVI, frequent alcohol use, and diabetes significantly decreased from 2008 to 2019, while the prevalence of current tobacco use and hypertension remained unchanged from 2008 to 2019. According to the Global Nutrition Report (28), Sao Tome and Principe did not achieve their diet NCD targets, with still having high rates of obesity (19.7% in women and 8.9% in men). Similar to previous trend studies in India (29), Mongolia (30, 31) and Iran (32) having high body mass index and/or low physical activity increased over time. Although Sao Tome has implemented some national food and NCD policies, such as sugar-sweetened beverage tax and operational policy, strategy, or action plan to reduce unhealthy diet related to NCDs, additional implementation of some of the following are indicated food-based dietary guidelines, policy to eliminate industrially produced trans fatty acids, policy to reduce the impact of marketing of foods and beverages high in saturated fats, trans fatty acids, free sugars, or salt on children, and policy to limit saturated fatty acid intake (28). Regarding physical inactivity, the implementation of some of the following may help in increasing physical activity, including national physical activity communications campaigns, national mass participation events on physical activity, promotion of physical activity in different settings, brief intervention on physical activity in primary health care, quality physical education and national guidelines on physical activity in different age groups (16).

In this survey the prevalence of diabetes reduced over time, whereas in India (29), South Kivu, Democratic Republic of Congo (33), and Mozambique (34), the prevalence of diabetes increased over time. The unchanged current tobacco use in Sao Tome and Principe may be attributed to reduced compliance with the MPOWER tobacco control strategy, e.g., cigarettes have not become less affordable, no smokefree laws in public places, no tollfree telephone quit line, no smoking cessation support available in the community and health care setting, and no anti-tobacco mass media campaigns (35).

Furthermore, frequent alcohol use was significantly reduced from 2008 to 2019 in this study, while the recorded alcohol per capita (15+) consumption also reduced from 8.3 in litres of pure alcohol in both sexes in 2010 to 6.8 in 2016 (36). Compared to other African countries, having 3–7 risk factors for NCDs in this study (36.3% in 2008 and 31.7% in 2019) was higher than in Malawi (3–7 risk factors, 16.5%) (8) and Zambia (26.7%, 3–10 risk factors) (9). The prevalence of overweight/obesity in 2019 (51.0%) and the prevalence of diabetes (1.2%) in 2019 was similar or lower than in another island country in Africa in Comoros (50.8% overweight/obesity and 8.5% diabetes) (6, 7), but in terms of overweight/obesity higher than in Malawi (26.5%) (8) and Zambia (24.4%) (9). The prevalence of hypertension (33.5% in 2019) was similar to Malawi (32.9%) (8) but higher than in Zambia (18.9%) (9), the prevalence of current tobacco use (8.8% in 2019) was lower than in Malawi (14.1% current smokers) (8), and in Zambia (10.7% daily tobacco use) (9), and the rate of IFVI (53.3% in 2019) was lower than in Zambia (90.4%) (9).

There was a male preponderance of current tobacco use and frequent alcohol use and a female preponderance of general overweight/obesity and low physical activity, and there were no sex differences in hypertension, diabetes and IFVI. In previous studies (11, 24), the prevalence of substance use in men was higher than in women, and the rate of obesity/obesity in women was higher than in men. As expected (10–13), older age increased the odds of overweight/obesity, hypertension, diabetes, and current tobacco use and middle age was associated with frequent alcohol use. Lower education was associated with IFVI as well as with frequent use of alcohol and inversely associated with overweight/obesity. Portuguese interview language increased the odds of IFVI, low physical activity, frequent alcohol use and overweight/obesity. These findings show that the seven specific risk factors for NCDs can be targeted differently according to gender, age, level of education and interview language.

Comprehensive interventions can be directed to promote the control of body weight, the cessation of smoking, healthy diet, and the examination and control of high levels of sugar and blood pressure.

Based on two national household surveys in adults from 2008 to 2019 in Sao Tome and Principe, we found that the prevalence of seven risk factors of NCD decreased among men but not women from 2008 to 2019. Overweight/obesity, and low physical activity increased, and IFVI, frequent alcohol use, and diabetes decreased, and hypertension and current tobacco use stayed the same. Several factors associated with the risk factors of NCD have been identified, including age, gender, level of education and interview language that can guide interventions.

Publicly available datasets were analyzed in this study. This data can be found here: World Health Organization NCD Microdata Repository at https://extranet.who.int/ncdsmicrodata/index.php/catalog/893.

The studies involving humans were approved by Ministry of Health Ethical Committee, Sao Tome and Principe. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.

SP and KP fulfil the criteria for authorship, conceived and designed the research, performed statistical analysis, drafted the manuscript, and made critical revisions of the manuscript for key intellectual content. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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