Comparison of two diets of varying glycemic index on carotid subclinical atherosclerosis in obese children

Abstract

Childhood obesity is associated with an increased carotid intima-media thickness (IMT) and stiffness. Increased carotid wall thickening and rigidity are considered markers of subclinical atherosclerosis. The aim of the present study was to test the effect of two hypocaloric diets of varying glycemic index on weight loss and markers of subclinical atherosclerosis in obese children. Seventy consecutive obese children attending the Outpatient Weight Clinic of the Department of Pediatrics were invited to participate in an intensive dietary protocol. Twenty-six accepted and were randomly assigned to two different groups: the first group followed a hypocaloric low-glycemic index diet and the second a hypocaloric high-glycemic index diet. Anthropometric measures and biochemical tests were performed in all children. Quantitative B-mode ultrasound scans were used to measure intima-media thickness (IMT) and diameters of the common carotid artery. Considering both groups together, at 6 months, body mass index decreased from 28.3 +/- 3.1 to 25.8 +/- 3.3 kg/m(2), systolic blood pressure from 119 +/- 12 to 110 +/- 11 mmHg (P< 0.001), diastolic blood pressure from 78 +/- 8 to 74 +/- 7 mmHg (P< 0.001), IMT from 0.48 +/- 0.05 to 0.43 +/- 0.07 mm (P< 0.001), stiffness from 3.57 +/- 1.04 to 2.98 +/- 0.94 mm (P = 0.002), and high-sensitivity C-reactive protein from 1.5 +/- 0.9 (values log transformed) to 0.4 +/- 1.1 (P < 0.001). No differences were detectable in fasting serum triglycerides, total cholesterol, and high-density lipoprotein cholesterol. Insulin resistance (calculated by the HOmeostatic Model Assessment index [HOMA] score) significantly reduced only in the low-glycemic-index diet group (P < 0.04). In conclusion, this study confirms a benefit of hypocaloric diets on carotid IMT and stiffness in obese children and demonstrates, for the first time, an amelioration of insulin sensitivity in obese children after a low-glycemic index diet. These results justify the advice to obese children to follow a low-glycemic index diet in order to improve their cardiometabolic profile.

C-Reactive Protein and Carotid Intima-Media Thickness in Children with Sleep Disordered Breathing

“…• 0.055 mm as a relevant difference in carotid IMT between the groups 18 • standard deviation of 0.06 mm 18 • α error (2-sided): 0.05 • β error: 0.20…”

The effect of low glycemic index diet on body weight status and blood pressure in overweight adolescent girls: a randomized clinical trial

“…A long-term parallel clinical trial conducted on 26 obese subjects aged 7-13 years demonstrated that BMI was decreased after consuming either a hypocaloric LGI diet or hypocaloric HGI diet [10]. In addition, a significant reduction in WC (not in BMI) was also reported for hypocaloric LGI diet consumers.…”

“…It was suggested that an ad libitum low glycemic index (LGI) diet could not influence the blood pressure among healthy overweight women [9]. The effects of GI diet on obesity in childhood were assessed in a study by Iannuzzi et al [10]. This clinical trial conducted among obese children could not find any beneficial effect from hypocaloric LGI diet on blood pressure [10].…”

“…The effects of GI diet on obesity in childhood were assessed in a study by Iannuzzi et al [10]. This clinical trial conducted among obese children could not find any beneficial effect from hypocaloric LGI diet on blood pressure [10]. This study was conducted on both genders with an age range of 7 to 13 years, with different pubertal status.…”

The Effectiveness of Different Diet Strategies to Reduce Type 2 Diabetes Risk in Youth

“…In another RCT, 26 children were randomly assigned to either a hypocaloric lower-GI (GI: 60) or a hypocaloric higher-GI (GI: 90) diet. After six months, insulin resistance was significantly reduced only in the lower-GI diet group (homeostatic model assessment of insulin resistance (HOMA-IR); higher-GI, baseline: 3.2 ± 1.6, 6 months: 3.2 ± 1.8, p = 0.98; lower-GI, baseline: 3.1 ± 1.5, 6 months: 2.4 ± 1.1, p = 0.04) [35]. In another RCT, consumption of a higher glycaemic load diet was associated with less weight loss even when adjusted for sex and pubertal status ( R 2 = 0.11, p = 0.007) [36].…”