Title

Effect of carbohydrate restriction and American Heart Association diets on the clinical features of the metabolic syndrome, the inflammatory response and lipoprotein metabolism in young Emirati adults

Date of Completion

January 2009

Keywords

Health Sciences, Nutrition|Health Sciences, Public Health|Biology, Physiology

Degree

Ph.D.

Abstract

The incidence of diabetes mellitus (DM) in the UAE is one of the highest world-wide. The metabolic syndrome (MetS) characterized by central obesity, high blood pressure and dyslipidemias predisposes for the development of DM. The presence of MetS was assessed in a population of overweight/obese individuals by randomly screening 227 subjects, 18-50 (30.2 ± 8.4 y), from Al-Ain city, Emirate of Abu Dhabi. 92 subjects (40.5%) were identified as having MetS. The most relevant clinical criteria associated with MetS were large waist circumference (WC), high systolic blood pressure and low HDL cholesterol (HDL-C). ^ Dietary interventions were conducted in 39 subjects. Initially, all individuals followed a carbohydrate restricted diet (CRD) with 25% energy from carbohydrate. After 6 wk, half of the subjects (n=19) were switched to the low fat diet (55% energy from carbohydrate) recommended by the American Heart Association (AHA group) while the other half (n=20) continued with the CRD diet for additional 6 wk (CRD group). Diet records indicated high compliance with the dietary guidelines. At wk 6, all subjects presented decreases in body weight (P < 0.0001), WC (P < 0.001), body fat (P < 0.0001) and plasma triglycerides (TG) (P < 0.0001). Significant decreases were also seen in plasma LDL cholesterol, blood pressure, insulin and inflammation markers while a significant increase in adiponectin was observed. After 12 wk, these positive changes persisted for all subjects independent of diet. However, body weight, plasma TG, insulin and plasma glucose were lower in the CRD (P < 0.05) compared to the AHA group. ^ The large atherogenic VLDL subfraction was decreased over time for all subjects (P < 0.01) with a more pronounced decrease (P <0.05) in the CRD compared to the AHA group. Medium and small LDL particles and apolipoprotein B decreased for all subjects (P < 0.01) rendering a less atherogenic lipoprotein profile. These studies indicate that CRD can effectively be used as a dietary intervention to decrease the biomarkers of the MetS and to reduce the number of atherogenic particles in plasma in young Emirati. Further, CRD was a better option to maintain low plasma TG and glucose and to improve insulin sensitivity compared to the AHA diet. ^