Lipoprotein(a) predicts the development of diabetic retinopathy in people with type 2 diabetes mellitus

Background Lipoprotein(a) [Lp(a)] has mainly been considered to be a predictor of the incidence of cardiovascular disease. In addition, previous studies have shown potential linkage between Lp(a) and diabetic microvascular complications. Objectives We investigated the incidence and risk factors for the development of diabetic retinopathy (DR) in patients with type 2 diabetes. Methods A total of 787 patients with type 2 diabetes without DR were consecutively enrolled and followed up prospectively. Retinopathy evaluation was annually performed by ophthalmologists. The main outcome was new onset of DR. Results The median follow-up time was 11.1 years. Patients in the DR group had a longer duration of diabetes (P <.001), higher baseline HbA_1c (P <.001), higher albuminuria level (P =.033), and higher level of Lp(a) (P =.005). After adjusting for sex, age, diabetes duration, presence of hypertension, renal function, LDL cholesterol, mean HbA_1c, and medications, the development of DR was significantly associated with the serum Lp(a) level (HR 1.57, 95% confidence interval [1.11-2.24]; P =.012, comparing the 4th vs 1st quartile of Lp(a)). The patient group with the highest quartile range of Lp(a) and mean HbA_1c levels ≥7.0% had an HR of 5.09 (95% confidence interval [2.63-9.84]; P <.001) for developing DR compared with patients with lower levels of both factors. Conclusions In this prospective cohort study, we demonstrated that the DR was independently associated with the serum Lp(a) level in patients with type 2 diabetes.