Relationship of glycaemic index with cardiovascular risk factors: analysis of the National Diet and Nutrition Survey for people aged 65 and older

Abstract

Objective: To identify associations between dietary glycaemic index (GI) and weight, body mass index and other risk factors for cardiovascular disease (CVD) -waist-tohip ratio (WHR), lipoprotein fractions, triacylglycerols (TAG) and blood pressure (BP) -in an older British population. Design: Cross-sectional dietary, anthropometric and biochemical data from the National Diet and Nutritional Survey for adults aged over 65 years were reanalysed using a hierarchical regression model. Associations between body weight, CVD risk factors, and dietary factors including GI and fibre intakes were explored among 1152 healthy older people living in the UK between 1994 and 1995. Results: In the unadjusted model, GI was significantly and directly associated with TAG (b ¼ 0.008^0.003) and diastolic BP (b ¼ 0.325^0.164) in males. These relationships were attenuated and non-significant after adjustment for potential confounding factors. WHR (b ¼ 0.003^0.001) and TAG (b ¼ 0.005^0.002) were significantly predicted by GI in males and females combined. The association with WHR was attenuated by adjustment for sex, age, region and social class; the relationship with TAG was non-significant after adjustment for other potential dietary confounders. Conclusion: After controlling for potential confounders, no clear links were detected between GI and body weight or other CVD risk factors. This study provides little evidence for advising the consumption of a low-GI diet in the elderly to prevent weight gain or improve other CVD risk factors. Keywords Glycaemic indexDietary fibre Elderly Weight Cardiovascular risk factors Cross-sectional surveyThe 2003 World Health Report attributes 29.2% of global deaths to cardiovascular disease (CVD) 1 . Overall, CVD is estimated to cost the UK close to £26 billion per year: 56% from direct health-care costs, 24% from reduced productivity and 16% as a result of informal care 2 . Advancing age is the principal non-modifiable risk factor for this disease 3 and, given that the UK population is ageing 4 , research efforts must focus on primary prevention to tackle the growing public health burden. High blood pressure (BP), smoking and high total cholesterol (TC) levels are the principal modifiable risk factors for CVD mortality 5 , although risk is not limited to these factors. A wealth of evidence is available describing the CVD risk attributable to adiposity (estimated, for example, using body mass index (BMI; kg m 22 ) 6 or waist-to-hip ratio (WHR) 7 ); serum TC, low-density lipoprotein cholesterol (LDL-C) 8 and high-density lipoprotein cholesterol (HDL-C) 9 ; serum triacylglycerols (TAG) 10 ; and dietary fats 11,12 . Less is known about the potential role of dietary carbohydrate 13 .The glycaemic index (GI) ranks carbohydrate-containing foods based on the increase in blood glucose following their consumption relative to that following consumption of an equi-carbohydrate portion of a reference food (white bread or glucose) 14 . This index is therefore more informative than measuring the quantity o...

Association of glycemic load with cardiovascular disease risk factors: The Women's Health Initiative Observational Study

“…Very few observational studies have investigated the association between GL (or GI) and BP. In the British National Diet and Nutritional Survey, GI was not associated with SBP or DBP in participants over 65 years of age [33]. Intervention studies have produced equivocal results, with some showing no effect of reduced-GL/GI diets on BP [34] and others showing trends toward reductions in both SBP and DBP on such diets [35,36].…”

Should glycemic index and glycemic load be considered in dietary recommendations?

“…The associations between GI and GL and different blood lipids are fairly consistent in the cross‐sectional studies, with protective effects of both GI and GL on TAG and HDL‐C 50,52,55–57,59 and no association with TC and LDL‐C 16,32,49,50,52,53 . On the other hand, the two prospective studies that examined associations between GI and GL and these blood lipids 53,54 were unable to replicate the findings from cross‐sectional studies; hence, GI and GL do not seem to influence changes in blood lipids.…”

“…Inverse cross‐sectional associations between GI and high‐density‐lipoprotein cholesterol (HDL‐C) were observed in six studies, 38,50–53,55 whereas four other cross‐sectional studies did not find significant associations 16,32,49,56 . Neither of the two longitudinal studies identified significant associations between GI and change in HDL‐C 53,54 (Table 5).…”

“…Triacylglycerol (TAG) was positively associated with GI in five cross‐sectional studies 32,38,50,51,56 but was not associated with GI in another three 16,49,53 . Two longitudinal studies observed non‐significant associations, although tendencies towards positive associations were noted 53,54 (Table 6).…”

“…Associations between GI and GL and various blood lipids among healthy individuals have been reported in 11 16,32,38,49–56 and 10 32,38,50,51,53–58 observational studies, respectively, most of which were cross‐sectional.…”