Anthropometric indices as determinants of haemorheological cardiovascular disease risk factors in Nigerian adults living in a semi-urban community

Abstract

Background: Some epidemiological studies have found anthropometric indices to be related to cardiovascular disease risk factors. Fibrinogen--an acute phase reactant protein--is central in the haemostatic system. Its associations with cardiovascular diseases have been well documented. A possible association between measures of body fat and fibrinogen has been reported.

Aims: To study the relationship of fibrinogen (PFC), plasma viscosity (PV) and haematocrit (HCT) with measures of obesity (body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR)) in apparently healthy Nigerians living in Ilisan-Remo, a semi-urban community.

Subjects and methods: The study population comprised of apparently healthy mono-ethnic Nigerians living in Ilisan-Remo town. Obesity was measured using the body mass index, waist circumference, waist-to-hip ratio and waist-to-height ratio. Blood samples were analyzed for rheological parameters (plasma fibrinogen, plasma viscosity, haematocrit and the erythrocyte sedimentation rate (ESR) using standard methods.

Results: A total of 122 subjects were studied, 46 males (mean age 57+/-15.7 years) and 76 females (mean age 58.92+/-17.99 years). The mean systolic blood pressure was 138.5 mmHg for males and 135.2 mmHg for females respectively. The independent variables (BMI, waist-to-hip ratio) were divided into 2 groups using the 75th percentile cut off. In the BMI group, the diastolic blood pressure, haematocrit and plasma viscosity were significantly higher in males (p<0.0001) in the >75th percentile group but not in females. Using the waist circumference; plasma viscosity and diastolic blood pressure were higher in males (p<0.0001) in the >75th percentile group. In females the haematocrit and blood viscosity were significantly higher (p=0.0074, p=0.0434) respectively in the >75th percentile group. Using stepwise multiple regression analysis, the waist circumference and BMI were found to be significant determinant for systolic and diastolic blood pressure. The BMI was significant determinant for the haemorheological cardiovascular disease (HCVD) risk factors except fibrinogen. While the waist circumference was a significant predictor of all the haemorheological cardiovascular disease risk factors (p<0.0001).

Conclusion: While the BMI and the WHR may be good predictors of CVD (cardiovascular disease) risk factors, we have shown that the waist circumference may be a better predictor of haemorheological cardiovascular disease risk factors than the BMI in Nigerians.