Metabolic Syndrome in Indigenous Amerindian Women in Suriname; Less on Waist and More on Weight?

Background: The indigenous Amerindian populations living in the southern interior part of Suriname have to date largely maintained their traditional hunter-gatherer life-style. In this study we compared the prevalence of metabolic syndrome (MeTS) and its component risk factors between indigenous Amerindian women of the interior of Suriname, with indigenous Amerindian women living in the coastal-rural areas who have a more urbanized lifestyle. We focused on women since the Suriname Health study showed that Indigenous women had the second highest MeTS prevalence nationwide.

Methods: A subset of secondary data from the Suriname Health Study was used. The prevalence of cardiovascular risk factors and of MeTS and its component risk factors were compared between the two populations, using analyses of variance and chi-square tests.

Results: Both groups had comparable MeTS prevalence’s of almost 40%. Elevated fasting blood glucose occurred twice more frequently in the coastal-rural compared to the interior women (51.2% vs. 24.7%). The prevalence of pre-diabetes was statistically significantly higher in the coastal-rural compared to the interior (43.1% vs. 17.3%), while diabetes mellitus and hypertension rates did not differ statistically significantly between the two groups (resp. 19.1% vs. 14.1% and 5.8% vs. 4.1%). Elevated triglycerides were more than twice more prevalent in the interior compared to the coastal-rural area (43.1% vs. 17.3%), possibly related to alcohol consumption. The obesity prevalence was around 50% in the coastal-rural women, almost three times higher than in the interior, while both groups had comparable prevalence’s of an increased waist circumference and waist/height ratio (around 80%). Lifestyle differed statistically significantly between the coastal-rural and interior women: coastal-rural women smoked more, had less vigorous daily activities, more frequently consumed meals from restaurants or fast food and more frequently used sugary soft drinks.

Conclusion: Despite a comparable MeTS prevalence of almost 40%, behavioral and other CVD risk factors differed statistically significantly between women living in coastal-rural areas and those in the interior. Interior women had statistically significantly lower pre-diabetes and obesity rates. In both groups the majority of the women (around 80%) had an increased waist circumference, which could be common in Amerindian people, unrelated to cardiovascular risk and needs to be studied further.

Keywords: Indigenous; Amerindian; Suriname; Medical Mission; MeTS; Obesity; Waist cirumference; Hypertriglyceridemia; Lifestyle

List of Abbreviations: BMI: Body mass index; CVD: Cardiovascular disease; EFG: Elevated fasting glucose; HDL: High density lipoprotein; MeTS: Metabolic syndrome; WC: Waist circumference; WHO: World Health Organization

Epidemiological studies have revealed a high prevalence of obesity, type-2 diabetes and coronary heart disease in Indigenous populations who have undergone a rapid transition from a primitive to an urban life-style [1-3]. Throughout the world, such rapid changes mainly in diet and habitual lifestyle may thus lead to increases in the prevalence of cardiovascular disease (CVD) and diabetes mellitus [4]. Indigenous people in Latin America and the Caribbean also face these challenges. Rising problems of obesity, diabetes mellitus and hypertension have been recorded especially in reserves where Indigenous people have been forced to abandon their original physically intensive lifestyle and their diet [1,5]. On the other hand there are still Indigenous people which live in isolated communities maintaining more or less their traditional life style and experiencing a low disease burden of CVD [1,6].

The metabolic syndrome (MeTS) has been defined as a cluster of interconnected CVD risk factors which increase the risk of CVD and type-2 diabetes mellitus [7]. The prevalence of MeTS is increasing rapidly worldwide especially in developing countries and reflects a transition from a traditional to a Western-like lifestyle [8].

There are few data on MeTS in Indigenous populations in Latin America. A recent study has highlighted the alarming increase of weight excess and of the burden of non-communicable diseases, suggesting the prevalence of MeTS could be elevated among these Indigenous populations [9].

The current study focuses on Amerindian people of the Republic of Suriname. This country is located on the north-east coast of South America and is part of the Amazon River Basin. Its remote south and south-western interior part are inhabited by Indigenous populations belonging predominantly to the Trio people (Figure 1).

Their population size is about 2,500 [10]. They have largely maintained their traditional life-style of hunting, fishing, and crop cultivation. The Indigenous in the coastal-rural areas of Suriname belong predominantly to the Carib people who have been living in coastal-rural villages for decades in closer contact with urban areas through work, purchase of goods etc. Their population size is approximately 9000 (1.6% of the total population) [11].

In this study we compared the prevalence of MeTS and its component risk factors between Indigenous Trio women of the interior southern part of Suriname, with Indigenous women living in the coastal-rural areas of the country. We focused on women since the Suriname Health study showed that Indigenous women had the second highest MeTS prevalence nationwide [12].

The aim of this study was to assess whether there are differences in the magnitude of behavioural risk factors, MeTS and its component risk factors between Amazonian Indigenous hunter gatherer women living in the southern part (interior) of Suriname and Indigenous women living in the coastal-rural areas of the country.

For our analysis we used a subset of data collected from Indigenous female participants living in the coastal- rural areas and in the interior (south) of the country. We used secondary data from the Suriname Health Study, a cross-sectional national surveillance survey among people 15-64 years, on non-communicable disease risk factors carried out from March-September 2013 [13]. In this study a multistage cluster, household population cross-sectional design was used to select respondents aged 15 to 64 years, men and non-pregnant women, of the 6 main ethnic groups including the Indigenous [13].

The Indigenous participants from the interior of the country had been randomly selected from the largest Trio village Kwamalasamutu, located near the southern border with Brazil [13]. This Trio village was selected because of its representativeness and the relatively high population density, namely 20% of all interior indigenous Amerindians. The number of study participants from this village was oversampled to compensate for high travel costs to the other smaller settlements scattered over the interior [13]. The Indigenous participants from the coastal-rural districts of the country were randomly selected from coastal-rural clusters. This group was oversampled as well to compensate for the relatively small percentage of indigenous Amerindians in the Surinamese population [13].

Data were collected using the validated WHO STEPS to chronic disease risk factor surveillance tool, which uses three levels of data collection: Step1 (a validated questionnaire) included the recording of information on demographics and non-communicable disease (NCD) risk factors (smoking, physical activity, dietary habits such as consumption of fast food and restaurant food and sugary soft drinks); Step 2 (Physical measurements) included body weight and height, waist circumference (WC) and systolic and diastolic blood pressure measurements; Step 3 (Blood samples) included the collection of fasting (at least 12 hours overnight) blood samples for laboratory analysis on the blood glucose, cholesterol and triglyceride levels [13].

Body mass index (BMI) was based on measurements of weight and height and expressed as body weight in kilograms divided by the square of the height in meters. BMI categories were defined according to guidelines by the World Health Organization (WHO): underweight-standard weight BMI<25.0, Overweight BMI 25.0-29.9 and Obesity BMI≥30 [14]. The cut point of 80 cm (for women) for the WC was used to determine abdominal obesity [15]. The recommended cut point of 0.5 was used for the waist/height ratio [16].

Hypertension was classified as systolic blood pressure ≥140 and/or a diastolic blood pressure ≥90 and/or self reporting of being on anti-hypertension medication [17]. Diabetes mellitus was classified as a fasting blood glucose ≥7.0 mMol/L and/or self-reporting use of anti-diabetic medication. An 8 hours fasting blood glucose between 6.1-6.9 mMol/L was classified as pre-diabetes [18]. The cut points 1.29 mMol/L and 2.8 mMol/L were used to determine HDL-C dyslipidemia and hypertriglyceridemia respectively [19].

The definition of MeTS used in this article adheres to the IDF/AHA/NHLBI consensus [7], which is based on three or more of the following components: blood pressure >=130/85 or using anti-hypertensive medication; WC >=80 cm (for women); fasting glucose >=5.6 mMol/L and/or using anti-diabetic medication; HDL-C cholesterol<1.29 mMol/L or using lipid lowering medication; Triglycerides >=1.7 mMol/L or using lipid lowering medication.

The prevalences of behavioural risk factors (Step 1 measurements) between the two sub-populations were compared using the Chi square test. Continuous variables (Step 2 and Step 3 measurements) were expressed as means and standard deviations or, for the variables not normally distributed, the median and interquartile range were used. Analysis of variance (Student t test) and non-parametric tests were used to compare means between the two populations. Discrete variables were expressed as proportions with 95% confidence intervals. The prevalence of cardiovascular risk factors and of MeTS and its component risk factors were compared between the two populations using the Chi square test. All analyses were performed using the software Statistical Package for Social Sciences (SPSS) version 22. The statistical significance level was fixed at p<0.05.

The Suriname Health Study was approved by the Ethics Committee of the Ministry of Health of Suriname and written consent was obtained from the study participants [13].