Fasting insulin, insulin resistance, and risk of cardiovascular or all-cause mortality in non-diabetic adults: a meta-analysis

• Published in: Bioscience reports 2017-10, Vol.37 (5)
• Main Authors: Zhang, Xiaohong, Li, Jun, Zheng, Shuiping, Luo, Qiuyun, Zhou, Chunmei, Wang, Chaoyang
• Format: Article
• Language: English
• Subjects: Adult; Cardiovascular Diseases - blood; Cardiovascular Diseases - etiology; Cardiovascular Diseases - mortality; Fasting; Homeostasis; Humans; Insulin - blood; Insulin Resistance; Risk Factors
• ISSN: 0144-8463; 1573-4935
• DOI: 10.1042/bsr20170947

Studies on elevated fasting insulin or insulin resistance (IR) and cardiovascular or all-cause mortality risk in non-diabetic individuals have yielded conflicting results. This meta-analysis aimed to evaluate the association of elevated fasting insulin levels or IR as defined by homeostasis model assessment of IR (HOMA-IR) with cardiovascular or all-cause mortality in non-diabetic adults. We searched for relevant studies in PubMed and Emabse databases until November 2016. Only prospective observational studies investigating the association of elevated fasting insulin levels or HOMA-IR with cardiovascular or all-cause mortality risk in non-diabetic adults were included. Risk ratio (RR) with its 95% confidence intervals (CIs) was pooled for the highest compared with the lowest category of fasting insulin levels or HOMA-IR. Seven articles involving 26976 non-diabetic adults were included. The pooled, adjusted RR of all-cause mortality comparing the highest with the lowest category was 1.13 (95% CI: 1.00-1.27; =0.058) for fasting insulin levels and 1.34 (95% CI: 1.11-1.62; =0.002) for HOMA-IR, respectively. When comparing the highest with the lowest category, the pooled adjusted RR of cardiovascular mortality was 2.11 (95% CI: 1.01-4.41; =0.048) for HOMA-IR in two studies and 1.40 (95% CI: 0.49-3.96; =0.526) for fasting insulin levels in one study. IR as measured by HOMA-IR but not fasting insulin appears to be independently associated with greater risk of cardiovascular or all-cause mortality in non-diabetic adults. However, the association of fasting insulin and HOMA-IR with cardiovascular mortality may be unreliable due to the small number of articles included.