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

- Our study confirms elevated lipoprotein(a) level is an independent predictable risk factor for future development of new onset diabetic retinopathy in type 2 diabetes.
- A well-controlled glycemic group (mean HbA1c <7.0%) developed DR by less than half compared to the poorly glycemic-controlled group (mean HbA1c >9.0%) during the study period.
- Patients with the highest Lp(a) quartile concentration in type 2 diabetes had an increased risk for developing DR.
- Even if the mean HbA1c level was <7.0% during the observation period, the highest Lp(a) quartile group showed significantly increased risk for developing DR.

BackgroundLipoprotein(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.ObjectivesWe investigated the incidence and risk factors for the development of diabetic retinopathy (DR) in patients with type 2 diabetes.MethodsA 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.ResultsThe median follow-up time was 11.1 years. Patients in the DR group had a longer duration of diabetes (P < .001), higher baseline HbA1c (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 HbA1c, 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 HbA1c 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.ConclusionsIn this prospective cohort study, we demonstrated that the DR was independently associated with the serum Lp(a) level in patients with type 2 diabetes.