Flavonoid consumption associated with reduced CHD risk in diabetic women
MedWire News: Long-term intake of flavonoids improves the lipid profile and insulin sensitivity of women with Type 2 diabetes and reduces their risk for coronary heart disease (CHD), findings from a UK study suggest.
The researchers say that, until now, no long-term trials have been conducted to examine the effects of either isoflavones or flavan-3-ols on biomarkers for cardiovascular disease (CVD) risk, even though short-term studies have been suggestive of favorable effects.
In addition, gender disparities in the treatment and control of CVD risk factors have been reported, with poorer metabolic control observed in women with Type 2 diabetes, explain Aedín Cassidy (University of East Anglia, Norwich) and team.
"These data reinforce the need for effective preventative disease management strategies to reduce CVD risk associated with Type 2 diabetes, particularly in women," they say.
The team randomly assigned 93 postmenopausal women with Type 2 diabetes who were already on established statin and hypoglycemic therapy to consume 27 g of flavonoid-enriched chocolate (850 mg flavan-3-ols and 100 mg isoflavones) or placebo every day for 1 year. The researchers measured the patients' insulin, lipid, and glucose levels at baseline and at the end of the intervention.
As reported in Diabetes Care, the mean insulin level was reduced by a significant 0.8 mU/L in women who consumed the flavonoid-rich chocolate, compared with a 0.6 mU/L increase in those who did not.
In addition, homeostasis model assessment of insulin resistance (HOMA-IR) was significantly reduced by 0.3 in the intervention group compared with a 0.4 increase in the placebo group. And the mean quantitative insulin sensitivity index (QUICKI) was significantly increased by 0.003 in the intervention group compared with a 0.004 decrease in the placebo group.
The study also revealed that women in the intervention group showed a significant reduction of 0.11 mmol/L in low-density lipoprotein cholesterol compared with a 0.05 mmol/L increase in the placebo group.
Furthermore, the intervention had a significant impact on estimated 10-year CHD risk (calculated using the UK Prospective Diabetes Study algorithm) with a lower risk in the intervention group relative to placebo (0.1 vs 1.1%).
The authors say they observed no effects of the intervention versus placebo on blood pressure, glycated hemoglobin (HbA1c), or glucose.
"These data highlight the additional benefit of dietary flavonoids to standard drug therapy in managing CVD risk in these patients," write Cassidy et al.
The team says long-term studies are now required to determine whether these effects are restricted to populations of medicated postmenopausal women with established Type 2 diabetes and to determine whether chronic intake of flavan-3-ols or isoflavones is as effective when consumed independently.
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By Sally Robertson