BACKGROUND
Previous studies have demonstrated that cardiovascular risk is higher with increased lipoprotein(a) [Lp(a)]. Whether Lp(a) concentration is related to type 2 diabetes is unclear.
METHODS
In 26 746 healthy US women (mean age 54.6 years), we prospectively examined baseline Lp(a) concentrations and incident type 2 diabetes (n = 1670) for a follow-up period of 13 years. We confirmed our findings in 9652 Danish men and women with prevalent diabetes (n = 419). Analyses were adjusted for risk factors that included age, race, smoking, hormone use, family history, blood pressure, body mass index, hemoglobin A1c (Hb A1c), C-reactive protein, and lipids.
RESULTS
Lp(a) was inversely associated with incident diabetes, with fully adjusted hazard ratios (HRs) and 95% CIs for quintiles 2–5 vs quintile 1 of 0.87 (0.75–1.01), 0.80 (0.68–0.93), 0.88 (0.76–1.02), and 0.78 (0.67–0.91); P for trend 0.002. The association was stronger in nonfasting women, for whom respective HRs were 0.79 (0.58–1.09), 0.78 (0.57–1.08), 0.66 (0.46–0.93), and 0.56 (0.40–0.80); P for trend 0.001; P for interaction with fasting status 0.002. When we used Lp(a) ≥10 mg/L and Hb A1c <5% as reference values, the adjusted HRs were 1.62 (0.91–2.89) for Lp(a) <10 mg/L and Hb A1c <5%, 3.50 (3.06–4.01) for Lp(a)≥10 mg/L and Hb A1c 5%–<6.5%, and 5.36 (4.00–7.19) for Lp(a) <10 mg/L and Hb A1c 5%–<6.5%. Results were similar in nonfasting Danish men and women, for whom adjusted odds ratios were 0.75 (0.55–1.03), 0.64 (0.46–0.88), 0.74 (0.54–1.01), and 0.58 (0.42–0.79) for Lp(a) quintiles 2–5 vs quintile 1; P for trend 0.002.
CONCLUSIONS
Our results indicated that Lp(a) was associated inversely with risk of type 2 diabetes independently of risk factors, in contrast to prior findings of positive associations of Lp(a) with cardiovascular risk.
Homocysteine and Lipoprotein(a) Interact to Increase CAD Risk in Young Men and Women