Dose Response Meta - Analysis Of Cholesterol And Breast Cancer Risk

Objective:To evaluate the effect of high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C),dietary cholesterol and serum total cholesterol(T-C) on the risk of breast cancer.Methods: A literature search was performed up to November 2014 in PubMed, EMBASE, China National Knowledge Infrastructure and China Biology Medical literature database for relevant articles published in English or Chinese. Pooled relative risks(RRs) with 95% confidence intervals(CIs) were calculated with a random-effect model. The fixed or random effect model was selected based on heterogeneity. Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using the Begg,s test. The dose-response relationship was assessed by the restricted cubic spline model and the multivariate random effect meta-regression.Results: Data were obtained from 46 studies among 32 articles, including 1814649 participants. For serum HDL-C, 17 studies were included involving 106989 participants. For serum T-C, 14 studies were included involving 1195184 participants. For serum LDL-C, 5 studies were included involving 36113 participants. And for dietary cholesterol, 10 studies were included involving 476563 participants.The pooled RR(95%CI) of breast cancer was 0.79(0.68-0.93)for serum HDL-C, 0.91(0.83-0.99) for T-C and 1.22(1.04-1.43) for dietary cholesterol, respectively. No significant association [0.82(0.59-1.14)] was found between the risk of breast cancer and serum LDL-C. And evidence of a nonlinear association was found between breast cancer and HDL-C and dietary cholesterol, the risk of breast cancer decreased faster after the HDL-C level of 40 mg/d L, and the risk of breast cancer increased faster after the consumption of dietary cholesterol was higher than 315 mg/day.Conclusion: Serum HDL-C and T-C may be inversely associated with risk of breast cancer. And dietary cholesterol may be associated with the increased risk of breast cancer. The results need to be confirmed further.