Glycemic Index, Retinal Vascular Caliber, and Stroke Mortality

Abstract

Background and Purpose-It is unclear whether diets with high glycemic index (GI) and low cereal fiber (CF) are associated with greater risk of stroke. We aimed to assess the relationship between dietary GI and CF content, retinal microvasculature changes, and stroke-related mortality. Methods-The study consisted of a population-based cohort, 49ϩ years, examined at baseline (1992 to 1994). At baseline, participants completed validated food frequency questionnaires. Mean GI was calculated using an Australian database.Retinal arteriolar and venular diameters were measured from photographs. Mortality data were derived using the Australian National Death Index. Results-Over 13 years, 95 of 2897 participants (3.5%) died from stroke. Increasing GI (hazard ratio, 1.91; 95% CI, 1.01 to 3.47, highest versus lowest tertile) and decreasing CF (hazard ratio, 2.13; 95% CI, 1.19 to 3.80, lowest versus highest tertile) predicted greater risk of stroke death adjusting for multiple stroke risk factors. Persons consuming food in the highest GI tertile and lowest CF tertile had a 5-fold increased risk of stroke death (hazard ratio, 5.06; 95% CI, 1.67 to 15.22). Increasing GI and decreasing CF were also associated with retinal venular caliber widening (P trend Ͻ0.01). Adjustment for retinal venular caliber attenuated stroke death risk associated with high GI by 50% but did not affect the risk associated with low CF consumption. Conclusions-High-GI and low-CF diets predict greater stroke mortality and wider retinal venular caliber. The association between a high-GI diet and stroke death was partly explained by GI effects on retinal venular caliber, suggesting that a high-GI diet may produce deleterious anatomic changes in the microvasculature.

Dietary fibre and cardiovascular disease mortality in the UK Women’s Cohort Study

“…Few studies report fatal stroke events and total fibre intake but a lack of association was reported in one Japanese cohort for both men and women [45] and a cohort from the US [18]. Additionally fatal stroke risk was not associated with greater cereal fibre intake in an Australian cohort [51].…”

Identification of a Major Genetic Determinant of Glycaemic Index in Rice

“…A growing body of evidence from epidemiological and clinical studies points to the adverse health consequences of foods and diets rich in carbohydrates which are readily and extensively digested Hu et al 2001;Sluijs et al 2010). Mechanistic studies demonstrate that chronically elevated blood glucose levels induce deleterious structural changes in many tissues of the body, in particular the macro-and microvasculature (Kaushik et al 2009). Postprandial glycaemia is emerging as a clinically useful independent risk factor for cardiovascular disease in non-diabetics and those with established diabetes (Sheu et al 2011).…”

Macronutrients and type 1 diabetes (revision number 6)

“…Eight cohort studies were identified that presented evidence on cereal fibre intake and coronary events (Fehily et al, 1993;Pietinen et al, 1996;Rimm et al, 1996;Wolk et al, 1999;Liu et al, 2002;Mozaffarian et al, 2003;Streppel et al, 2008;Kaushik et al, 2009), six of which were included in a meta-analysis. Two cohort studies could not be included in a meta-analysis as they did not report the necessary data.…”

“…Two cohort studies could not be included in a meta-analysis as they did not report the necessary data. One indicated no significant association between cereal fibre and coronary events (Kaushik et al, 2009) while the other study did not report a statistical comparison (Fehily et al, 1993). One cohort study was subsequently identified in the update search (Eshak et al, 2010) (Cardio-metabolic review, Cardiovascular Disease chapter p 65-70, 73-75; Update search table 20).…”

“…One cohort study was identified that presented evidence on GI and the incidence of total cardiovascular disease (Levitan et al, 2007), which indicated GI was not associated with the incidence of all cardiovascular disease mortality. Five cohort studies were identified that presented evidence on GI and coronary and stroke events combined, all of which were included in a meta-analysis (Van Dam et al, 2000;Oh et al, 2005;Beulens et al, 2007;Levitan et al, 2007;Kaushik et al, 2009). One cohort study was subsequently identified in the update search, which pooled four Danish cohort studies together (Grau et al, 2011) (Cardio-metabolic review, cardiovascular disease chapter p 160-168; Update search table 36).…”