The Epidemiology of Non-Communicable Diseases Lifestyle Risk Factors in Tanzanian Population Groups

Background: The burden of non-communicable diseases (NCDs) is a global public health concern which so far has claimed more than 36 million lives worldwide. Four key lifestyles namely insufficient fruit and vegetable (FV) intake, insufficient physical activity (PA), harmful alcohol use and tobacco smoking are responsible for majority of the NCD disability adjusted life years (DALYs) (52.1%), whereas the rest are attributed to genetic and occupational risks. Low and middle income countries (LMIC) like Tanzania succumb to almost the entire NCD burden (>90%), while still being overwhelmed by the burden of communicable diseases amidst a debilitated health care system. Moreover, epidemiological evidence for aiding NCD interventions is least available in LMIC. In the absence of effective responses, the death toll may reach 44 million by 2020. This study is in line with the global call to address lifestyle risks through the “25 x 25” risks by the WHO coordinated leadership of “The Lancet NCD Action Group and NCD Alliance”. The “25 x 25” risks seeks to reduce 25% of lifestyle risks by the year 2025. Hence this study explores a semi-urban setting in Southern Tanzania to describe how far unhealthy practices have manifested different socio-demographic population groups and its relevance to the burden of NCDs; and from that proposes suitable public health responses.
Methods: This study employed a cross sectional design from the MZIMA open community cohort round 1 (2012-2013) and round 2 (2013-2014). The MZIMA cohort is lodged into the Ifakara Urban Health and Demographic Surveillance System (IU-HDSS). The WHO STEPS tool was adopted to answer questions on how often fruits and vegetables (FV) were consumed, in what portions and by whom and this information eventually was used to describe patterns of FV insufficiency. This work was able to describe fruit intake and vegetable intake patterns individually and thereby establish the respective intake limitations and importance in the overall population FV insufficiency. Furthermore, the study was also able to explore patterns of physical activity under the domain activities of “work”, “travel” and “recreation or leisure”. Moreover, intensities of activities described as “vigorous” and “moderate” were deduced and thereby the overall population moderate to vigorous physical activity (MVPA) was also deduced in a gender specific manner. In addition, the WHO STEPS tool was also used to establish alcohol use patterns in respect to frequency of alcohol consumption, amount of alcohol consumed, and type of alcohol consumed in different population groups with special interest on understanding the burden of heavy episodic drinking (HED) and use of local brew. Patterns of tobacco smoking captured as never, ever and daily smokers were useful in establishing associations with other lifestyle risks. Logistic regression models assessed the relation between NCD risky lifestyles and specific contextual factors also defined as social determinants.
Results: This study found that FV insufficiency was widely prevalent (82%), with vegetables being consumed daily by almost half of the population but in small portions, and with youth being most deprived. Use of fruits was found to be limited by indicators of low social economic status (SES). We also found that three quarters of the population were active enough, but majority among them were active to moderate intensity (59.5%) only. In a resource poor semi-urban setting were farming is still the most prevalent economic activity, dominance of moderate over vigorous intensity physical activity should be given closer monitoring because it could be a signal of a population becoming less active. It is such subtle changes in physical activity that eventually may lead to drop in the overall MVPA and consequently risk of insufficient PA and sedentary lifestyle. In addition, gender specific influence of age on physical activity was clear and statistically relevant. Young men were more likely to be more active than young women, but in old age the opposite was true. Moreover, people with high SES were more likely to be insufficient in PA than those with low SES. This study also found that HED was widespread (91.3%) among all drinkers with no significant gender or SES difference. Local brew (47.9%) was no longer the most popular alcoholic drink when compared to previous studies. Moreover, more women and youth binge drinkers consumed commercial alcoholic beverages. Furthermore, 25% of drinkers were also smokers which is an important predisposition to head and neck cancers.
Conclusion: This study contributes evidence to the global and national NCD research agenda, suggesting that the burden of NCD risky lifestyle in Southeastern Tanzania is substantial and highly complex within its context. This includes widespread insufficient FV, predominant moderate MVPA and alarming patterns of alcohol abuse that are further aggravated by the burden of smoking. These are quantitative findings which can be further strengthened by qualitative explorations to shed light on mechanization of NCD risky lifestyles in the study setting. The lifestyle profiles observed in this study demand urgent public health responses particularly targeting the specific needs of those socio-economically deprived as a matter of priority. Targeted public health action and priority setting and against specific risky lifestyles should further consider gender and age difference in vulnerability. These findings emphasis the need for active health education campaigns on the public health importance of NCDs and WHO lifestyle recommendations while promoting and facilitating environments for easy access to healthy choices. A string of promotional environments to strengthen specific healthy choices have been proposed. This includes introduction of indigenous vegetables into mainstream marketing and evidence-based farming to improve vegetable consumption. It is also proposed to explore the possibility of replacing expensive fruits with nutrient rich herbs and spices locally available and accessible to the majority at affordable prices. Others include infrastructural and policy adjustments necessary to support more population physical activity and FV intake. The study also proposes ways of strengthening the political environment for more successful implementation of the NCD policies, NCD regulations and the NCD research agenda. In addition, the study also describes the potential for using the existing national revenue collection system, health system, police, social welfare offices, law firms and others as platforms for monitoring patterns of healthy choices and its health and social impact across different geographic settings and population groups country wide.