title: Fasting insulin concentrations and incidence of hypertension, stroke, and coronary heart disease: a meta-analysis of prospective cohort studies.
abstract: BACKGROUND
  Insulin resistance is a precursor of numerous chronic diseases, including cardiovascular disease (CVD). The fasting insulin concentration is considered a reasonable surrogate of insulin resistance, especially among nondiabetic individuals.
  
  
  OBJECTIVE
  We aimed to quantitatively summarize the literature on the association of fasting insulin concentrations with risk of hypertension, stroke, and coronary heart disease (CHD) by conducting a meta-analysis of prospective cohort studies.
  
  
  METHODS
  Eligible studies were identified by searching PubMed and EMBASE through January 2013. Additional information was retrieved through Google Scholar or a hand review of the reference lists from relevant articles. Prospective cohort studies that reported RRs and corresponding 95% CIs for the association of interest were identified. Data were extracted independently by 2 investigators, and the weighted RRs and 95% CIs for the associations were obtained by using a random-effects model.
  
  
  RESULTS
  Of the 22 identified studies, 10 reported results on hypertension (36,617 individuals and 4491 cases), 7 on stroke (27,887 individuals and 1550 cases), and 9 on CHD (22,379 individuals and 1986 cases). Comparison of the highest with the lowest quantile of fasting insulin concentrations showed a pooled RR (95% CI) of 1.63 (1.35, 1.97) for hypertension, 1.18 (0.87, 1.60) for stroke, and 1.50 (1.28, 1.77) for CHD. Each 50-pmol/L increment in fasting insulin was associated with a 25% increase in risk of hypertension [RR: 1.25 (1.14, 1.36)] and a 16% increase in risk of CHD [RR: 1.16 (1.10, 1.22)] but was not associated with risk of stroke [RR: 0.999 (0.99, 1.01)].
  
  
  CONCLUSIONS
  A higher fasting insulin concentration or hyperinsulinemia was significantly associated with an increased risk of hypertension and CHD but not stroke. This meta-analysis suggests that early fasting insulin ascertainment in the general population may help clinicians identify those who are potentially at high risk of CVD.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington, IN (PX and KH); the Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC (YW); and the Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA (QH).
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Xun
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Qianchuan
authors.initials: Q
authors.lastname: He
authors.forename: Ka
authors.initials: K
authors.lastname: He
mesh_terms: D015331:Cohort Studies; D003327:Coronary Disease / Q000453:epidemiology / Q000209:etiology*; D005215:Fasting; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D006973:Hypertension / Q000453:epidemiology / Q000209:etiology*; D015994:Incidence; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology*
chemical_list: D007328:Insulin