GENDER DIFFERENCES IN LIPOPROTEIN RESPONSES TO DIET

Gender and dietary saturated fat remain two strong predictors of coron ary heart disease susceptibility. In a retrospective meta-analysis of five studies, we analyzed the impact of gender and diet composition on lipoprotein change, or 'response' (DELTA) in 63 normolipidemic subjec ts fed two contrasting, metabolically controlled diets. One diet had a low polyunsaturated to saturated fatty acid ratio (low P:S) and the s econd, a high P:S ratio in a crossover design. Lipid profile 'responsi veness' was calculated as the adjusted difference (mg/dl) following ea ch diet period. Multivariate analysis of variance revealed that trigly ceride (DELTATG), very low density (DELTAVLDL-C), and high density lip oprotein cholesterol responses (DELTAHDL-C) were the only statisticall y significant, gender-specific lipid responders. Difference in low den sity lipoprotein (LDL-C) response to diet was similar between the sexe s. Multiple regression analysis identified the independent predictors of DELTAHDL-C for males and females. In females, the HDL-C lowering wa s predicted by the percentage increase in polyunsaturated fatty acids, baseline HDL-C levels and, inversely by DELTATG. The male predictor o f DELTAHDL-C was diet alone (replacement of saturated fat by dietary p olyunsaturated fatty acids). Results showed that while normolipidemic males and females show similar reductions in LDL-C following dietary c hange, DELTAHDL-C is gender-specific, with females showing a greater f all in the potentially 'beneficial' HDL-C than males. We conclude that a diet crossover may be of less benefit to normolipidemic females tha n to males, due to HDL-C lowering. Gender and diet may both become piv otal considerations in achieving plasma lipid goals.