Non-high-density lipoprotein cholesterol changes in middle-aged obese men with and without metabolic syndrome during weight loss

Non-high-density lipoprotein (non-HDL-C) is the best predictor of coronary artery disease and stroke. Studies have shown that weight loss decreases non-HDL-C levels. However, whether diet-induced weight loss in individuals with and without metabolic syndrome causes a reduction in non-HDL-C levels remains unclear. We investigated the effects of weight loss on non-HDL-C levels in 34 middle-aged obese men with and without metabolic syndrome classified using National Cholesterol Education Panel Adult Treatment Panel III criteria (metabolic syndrome, n=17; non-metabolic syndrome, n=17). We conducted a 12-week dietary intervention using a low-carbohydrate, -fat, and -protein diet to reduce body weight. A significant decrease in body weight and body mass index in both groups was observed. However, the non-HDL-C level after weight loss was significantly decreased in the metabolic syndrome group (151.9±6.8 to 131.4±6.2mg/dL, P<0.01) but not in the non-metabolic syndrome group (152.1±8.2 to 141.2±8.1mg/dL, P>0.05). Levels of apolipoprotein AII and B, but not AI, were similarly decreased in both groups (P>0.05). Pearson correlation analysis showed that the change in non-HDL-C levels in the metabolic syndrome group was strongly associated with levels of total cholesterol, fasting insulin, and alanine and aspartate transaminase, as well as homeostatic model assessment index, diastolic blood pressure, and maximal oxygen uptake (P<0.05). These results demonstrated that diet-induced weight loss without physical activity decreases non-HDL-C levels, an important factor associated with changes in cardiorespiratory fitness and insulin sensitivity, in obese individuals with metabolic syndrome.