Diets high in carbohydrate may not be appropriate for rs328 G carriers with the metabolic syndrome.

The objective of this study was to test how the genetic polymorphisms located within the lipoprotein lipase (LPL) locus would modulate the relationship between a diet high in carbohydrate and insulin resistance related traits in metabolic syndrome adults. A one year nutritional intervention study focusing on education to increase dietary intake of whole grain, vegetable and fruit, and to reduce the intake of sodium, simple sugar and dietary fat (especially cooking oil and pork lard) was conducted. Two districts in Shanghai, China were randomly selected to be the intervention and control group, and patients (n=235) with metabolic syndrome within these two districts were selected based on a multistage sampling method. Fasting glucose was reduced in rs328 CC homozygotes (p=0.028) but not G carriers (p=0.686) within the intervention group. Also an ancillary study with greater statistical power by combining the baseline measurements across both the intervention and control groups was conducted to test the cross-sectional statistical interactions between carbohydrate/fat and lipoprotein lipase genotypes for homeostasis model assessment of insulin resistance/insulin/fasting glucose. Increased carbohydrate intakes were positively associated with homeostasis model assessment of insulin resistance and insulin in rs328 G carriers but not CC homozygotes (p for interaction was 0.025). These results indicate that diet high in carbohydrate may not be suitable for metabolic syndrome rs328 G carriers, calling for the development of personalized dietary intervention for metabolic syndrome subjects.