A prospective study on hyperglycemia and retinopathy of prematurity

OBJECTIVE: Retinopathy of prematurity (ROP) constitutes a significant morbidity in premature infants that can lead to blindness. Multiple retrospective studies have identified neonatal hyperglycemia as a risk for developing ROP. However, in the absence of any reported prospective study, it is not clear whether hyperglycemia is associated with ROP independent of the commonly associated comorbidities. The objective of this study was to investigate whether hyperglycemia in premature infants is independently associated with ROP. STUDY DESIGN: Premature infants ( < 1500 g or <= 32 weeks gestational age) were enrolled in a prospective longitudinal cohort study. All demographic, clinical and laboratory data were collected. Bedside whole-blood glucose concentration was measured every 8 h daily for 7 days. For any glucose reading <50 or>150 mg dl(-1), serum sample was sent to the laboratory for confirmation. Hyperglycemia was defined as any blood glucose level 150 mg dl(-1). ROP patients were compared with non-ROP patients in a loivariate analysis. Variables significantly associated with ROP were studied in a logistic regression model. RESULT: A total of 65 patients were enrolled with gestational age 31.1 +/- 1.2 weeks and birth weight 1385 226 g. Thirty-one patients (48%) were identified with hyperglycemia. On eye examination, 19 cases (29.2%) had -ROP (13 with stage 1, 4 with stage 2 and 2 with stage 3). There were more cases of ROP in the hyperglycemia group compared with the euglycemia group (45% vs 15%, P=0.007). Patients who developed ROP had significantly higher maximum and average glucose concentrations when compared with non-ROP patients. Multiple factors have been associated with ROP on bivariate analysis, including gestational age, exposure to oxygen, respiratory support and poor weight gain. However, in a logistic regression model including all significant variables, average blood glucose in the first week of life was the factor independently associated with ROP with an odds ratio of: 1.77 (95% confidence interval: 1.08 to 2.86), P=0.024. CONCLUSION: In a cohort of premature infants, elevated average blood glucose concentrations in the first week of life is independently associated with the development of ROP.