High adiponectin levels linked to reduced risk for CHD in women
MedWire News: Women with high levels of total adiponectin, high molecular weight (HMW) adiponectin, or a high ratio of HMW/total adiponectin may have a lower risk for incident coronary heart disease (CHD), suggest study findings.
The results also showed these associations were mediated by parameters related to glucose and lipid metabolism and inflammation, especially high-density lipoprotein (HDL) cholesterol levels.
Until now, results from prospective studies have provided inconclusive results supporting an inverse association between adiponectin levels and risk for CHD, with most prior studies conducted among predominantly male populations, say the researchers.
Tobias Pischon (Max Delbrueck Center for Molecular Medicine [MDC] Berlin-Buch, Germany) and colleagues identified 30,111 women (aged 30-55 years) from the Nurses' Health Study, 468 of whom developed nonfatal myocardial infarction or fatal CHD during 14 years of follow-up.
Participants free of cardiovascular disease were matched for age, smoking status, fasting status, and date of blood sampling in a 2:1 ratio.
Total cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, C-reactive protein (CRP), and HbA1c levels were significantly higher among women with CHD, while HDL cholesterol levels were significantly lower compared with controls.
Women who developed CHD had significantly lower mean plasma levels of total (8.17 vs 9.33 mg/l) and HMW adiponectin (4.78 vs 5.67 mg/l), and a lower HMW/total adiponectin ratio (0.545 vs 0.575) compared with healthy controls.
Indeed, women in the highest compared with the lowest quintile of total adiponectin (14.69 vs 4.83 mg/l), HMW adiponectin (9.83 vs 2.21 mg/l), or HMW/total adiponectin ratio (0.71 vs 0.44) had respective relative risks (RRs) for developing CHD of 0.50, 0.53, or 0.63 after adjusting for matching variables, family history of myocardial infarction, body mass index, alcohol consumption, physical activity, hormone replacement therapy use, hypertension, and LDL cholesterol levels.
When the team analyzed findings on a continuous scale, two-fold higher levels of total adiponectin, HMW adiponectin, or the HMW/total adiponectin ratio were associated with a significant 30%, 22%, or 33% reduced risk for CHD, respectively.
However, after further adjustment for diabetes, HDL cholesterol, HbA1c, and CRP levels, these associations were attenuated and became nonsignificant. This finding suggests that the reduction in risk associated with adiponectin is largely mediated by parameters relating to glucose and lipid metabolism and inflammation.
Similar findings were seen for the multivariate-adjusted association between adiponectin and nonfatal myocardial infarction and fatal CHD, with a two-fold higher level of total adiponectin, HMW adiponectin, and HMW/total adiponectin ratio associated with a 29%, 21%, and 34% reduced risk of nonfatal MI and a 37%, 29%, and 51% reduced risk for fatal CHD, respectively. As in the main analysis, these RRs were attenuated after adjusting for HDL cholesterol.
"Although all measures of adiponectin were strongly inversely associated with CHD among women, our data do not support the hypothesis that HMW adiponectin or HMW/total adiponectin ratio is more closely related to risk of CHD than total adiponectin," say the researchers in the journal Atherosclerosis.
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By Ingrid Grasmo