Excess body fat is well documented as being a risk factor for numerous chronic conditions such as diabetes, hypertension, hyperlipidaemia and cardiovascular diseases[18
]. Studies of anthropometric measures among adult populations of sub-Saharan Africa countries are limited and weight, and BMI are the most common indicators which have been used to assess overweight and obesity prevalence. The CamBoD Baseline Survey, was the first large scale study of cardiovascular risk factors, using standardized methodology, to be conducted in Cameroon, and the first using the WHO STEPS methodology from Sub-Saharan Africa. This study updates the data on overweight and obesity using a range of anthropometric parameters in the adult population of men and women living in urban area of Cameroon.
This study highlights the high prevalence of overweight and obesity in Cameroon, whether measured by BMI, WC or WHR, and highlights the emergence of non-communicable diseases and their risk factors as major contributors to the burden of ill-health in Sub-Saharan Africa, particularly among urban populations.
The prevalence of obesity estimated from the CamBoD Baseline survey was particularly high in women, and increased markedly between 15–34 and 35–44 years in both sexes. Prevalence of obesity was five times higher in females aged 15–34 years compared to men. Comparison with previous findings in Cameroon is difficult because of different methodologies. However, the prevalence of obesity, estimated from this study is consistent with already published results. Thus, Sobngwi et al. reported a prevalence of BMI obesity of 5.4% in men and 17.1% in women [4
] among urban Cameroonians in 2002, slightly lower than found in this study. Pasquet et al [5
] also reported comparable results. Lower prevalences have been reported in other urban settings in Africa [19
], though even higher prevalences were found by Puoane et al who reported a prevalence of 9.2% in men and 42% in women in the urban adult population of South Africa [21
Obesity as estimated by BMI (a measure of total body fat) and central obesity as estimated by WC and WHR was low among men in the younger age group (0.9–2.4%) and moderate among women (11.8–18.5%). BMI defined obesity increased to 13.6% in 35–44 years old men, and then remained fairly constant in the older age groups, while central obesity measured by WHR continued to increase to a maximum (11.8%) in the >55 years group. BMI defined obesity increased to a peak of 41.4% in the 45–54 years group in women, and increased steadily across all age groups to a maximum of 66.5% in women aged >55 years.
The anthropometric measurements except WHR were strongly correlated with each other. The correlation of indices of overall and central obesity is highly suggestive of an association between increased overall obesity (as measured by BMI) with increased visceral fat (WC in this case). We found that mean WC, more than WHR, increased across overall obesity (BMI) categories in both genders. Similar results were reported in the urban female population of Morocco by Belahsen et al [22
], and by Sargeant et al in the urban adult population of Jamaica [23
]. It is likely therefore that BMI and WHR provide different measures of almost the same phenomenon.
Visceral fat is more metabolically active than subcutaneous fat, and hence may be more deleterious to health [9
]. Several studies have found a strong association between visceral fat and cardiovascular risk factors [24
]. WC is a practical measure of intra-abdominal fat mass [25
] and recommendations have been formulated to use it in the identification of people in need of intervention for cardiovascular risk reduction [28
]. In men and women adults of urban Cameroon, WC was strongly correlated with BMI (r ≈ 0.8 in men and women respectively) but showed moderate correlation with WHR (0.6 for men and 0.4 for women). These findings suggest that defining obesity on the base of waist circumference may be an equally or more valid and useful method for use in epidemiological research and clinical practice, though further research is needed to demonstrate this unequivocally
Studies in developed countries show an inverse (negative) relationship between education and obesity, particularly among women: the lower the education or the social class, the higher the prevalence of obesity. However, in developing societies, a strong positive relationship often exists between SES and obesity among men, women, and children [31
]. In the present paper, the positive association between obesity and duration of education, as measured by the number of year of schooling was clearly seen in both genders when obesity was defined by BMI or WC. The same pattern was less evidence for WHR, particularly in women where there was some evidence of an inverse gradient. Number of years of education can be used as a proxy for socioeconomic status in this population; the greater the number of year of education, the higher the SES. It is likely that higher socioeconomic status in developing countries is characterized by a westernization of the lifestyle, including reduced physical activity, more sedentary life and adoption of higher energy, higher fat diets; all of which may lead to an increase in obesity. However, it is also possible that if westernization of diet and reduced physical activity becomes more general in developing country populations, the familiar inverse association of obesity with socioeconomic status will emerge.