Temporal changes in anthropometric parameters and lipid profile according to body mass index among an adult Iranian...

To examine changes in anthropometric parameters and lipid profiles over a period of 3.6 years in an Iranian adult population according to body mass index (BMI) groups.

Between 1998 and 2001 (phase 1) and 2002 and 2005 (phase 2), 5,618 nondiabetic Iranian adults aged > or =20 years were examined. Analysis of covariance was used to delineate trends in anthropometric parameters as well as total and low- and high-density lipoprotein cholesterol (TC, LDL-C and HDL-C, respectively) across BMI groups.

Although BMI increased in women, this increase was not significant in obese persons. Among the men, however, a significant increase in BMI was observed only in lean persons. Waist circumference (WC) increased across all BMI groups in both sexes. A significant decrease was observed in TC [men: -0.83 mmol/l, 95% confidence interval (CI) -1.27 to -0.40; women: -0.78 mmol/l, CI -0.97 to -0.60] and LDL-C (men: -0.63 mmol/l, CI -1.13 to -0.13; women: -0.51 mmol/l, CI -0.78 to -0.24). A significant decrease in mean HDL-C was observed only among men (-0.09 mmol/l, CI -0.13 to -0.04), with no difference among BMI groups (p = 0.3). There were no significant decreases in TC/HDL-C and LDL-C/HDL-C ratios in men or women.

Despite an increase in WC, favorable trends were observed in TC and LDL-C levels. The favorable trend in TC levels was counterbalanced by changes in HDL-C, as reflected by the absence of a significant decrease in TC/HDL-C or LDL-C/HDL-C.