The results suggest that the indigenous people have a different risk factor profile for cardiovascular disease (i.e. comparable rates of obesity and lower rates of DM, hypertension and dyslipidemia except HDL levels) compared to those living in urban and rural areas. One likely explanation for this could be the changes in life styles resulting in increasing rates of over-weight and obesity, while the prevalence of diabetes and hypertension have lagged behind. If this hypothesis is correct, this population group would face higher rates of these diseases in the near future.
In Sri Lanka, the prevalence of obesity, overweight, hypertension and diabetes are higher in urban than rural areas. A study done in 2012 in Kaluthara district showed that obesity was more prevalent in urban areas and among rich people.7 SLDCS data in 2005-2006 showed that diabetes prevalence was significantly higher in the urban population compared with rural; 16.4% vs. 8.7% (P < 0.001). A study done in 2012 in Kaluthara district has shown that diabetes was more prevalent in urban areas and among rich and affluent people, which indicated that Sri Lanka was in the early stage of the epidemic.8
The projected diabetes prevalence in Sri Lanka for the year 2030 is 13.9%.10 Though there are differences in the prevalence according to regions and social strata, Sri Lanka as well as the entire world will experience a marked rise in obesity and diabetes in the future. Rural and indigenous communities may lose their immunity against such trends as suggested by recent studies.
Although the response rate is around 39%, our data shows that the current rates of obesity and diabetes in indigenous people have increased compared to the study in 2013 in Pollebedda.14 Rising trends of Diabetes in our population warrants further studies into risk factors particular to this population. Contributing factor may be change in dietary pattern consist of more carbohydrates as appose to the traditional diet consisting high fiber and high protein.15 Particularly in the Vedda community this may be due to change in life style which earlier consist of traditional hunting but now predominantly farming and having access to high calorie food.15
Rising trend of both diabetes and obesity in our population raises possibility of obesity as a cause of the diabetes epidemic even in this community. Though this study was from a single Vedda community, it is compatible with global trend seen with regards to cardiovascular risk factors in indigenous populations. Although there’s genetic variations among different indigenous populations around the world due to evolution and anthropological factors, evidence is there to indicate that there is definitely a rising trend in cardiovascular risk factors in indigenous communities. Studies from several countries show that the indigenous communities have higher prevalence rates of obesity and diabetes than the national average.
Prevalence of obesity and diabetes in Australian indigenous aboriginal population (2.5% of total population) are 27% and 7% compared to national prevalence of 22% and 4%, repectively.18 Similarly, in New Zealand Maori indigenous population (15% of total population), the prevalence of obesity and diabetes are 42% and 8% compared to national prevalence of 27% and 5%, respectively.18 In USA, in indigenous American Indians and Alaskans (1.7% of total population), the prevalence of obesity and diabetes are 42% and 15% compared to national prevalence of 33% and 8%, respectively.18 Furthermore, population surveys in these 3 countries have shown that compared to non indigenous population, indigenous population shows higher rates of unhealthy dietary habits and sedentary behavior patterns.18 In Malaysia, Orang Asli indigenous population (0.6% of total population), the prevalence of obesity and diabetes are 16.8% and 4.6% compared to national prevalence of 17.7% and 20.8%, repectively.20 There is a rise in the prevalence of cardio metabolic risk factors in indigenous tribes in Malaysia when compared to 20 years ago where urbanization has been implicated as a possible cause.20
More recent study involving Canadian First Nations communities (indigenous population) in 2018 showed that poor education, racism, difficulty accessing routine health care and not having access to a primary health care provider are some of the risk factors associated with higher rates of cardiovascular disease.19 Furthermore, it was revealed that greater the burden of socioeconomic hardship, the greater the burden of cardiovascular risk factors for a given community.19 In a central Australian aboriginal community in 2009, depression and unemployment were identified as risk factors for having increased risk for cardiovascular disease.20
In Sri Lanka, these scattered groups of indigenous populations are undergoing demographic transition (9.9% elders above 65 years in our study vs. 8.1% nationally). Furthermore, they experience greater socio economic hardship due to social isolation and poverty.15 Poor health care seeking behavior and limited access to health care due to limitation in transport are clearly identified in these communities, particularly as these communities are among the poorest in the country with most families having a household income of less than Rs.5000/= per month.15 In Australia as well cardiovascular risk factors in indigenous communities were associated with psychological factors and socioeconomicindicators.21
A comprehensive strategy involving identification of unique risk factors, implementation of culturally appropriate preventative measures and improving accessibility to health care is highly recommended to prevent exponential rise in risk factors for cardiovascular diseases such as obesity and diabetes in these indigenous communities. Because it is clearly evident that Sri Lankan indigenous community is also following the global trend of increasing cardiovascular risk factors in indigenous populations. Potential local strategy would be implementing a separate health promotion strategy in the districts with indigenous communities, targeting prevention of cardiovascular risk factors using dietary modifications and physical activities which is acceptable to their cultures.
As studies from several countries indicate that the indigenous populations are increasingly susceptible to develop obesity and other coronary artery risk factors preventative strategies targeting indigenous communities are coming to the focus of discussion in other countries as well.17