Association of hemoglobin with decreased prevalence of diabetic retinopathy among Tibetan male patients.

INTRODUCTION

It has been reported that hemoglobin (Hb) levels are negatively associated with the prevalence of diabetic retinopathy (DR). This study aims to investigate the relationship between Hb levels and DR prevalence among highlanders, who exhibit elevated Hb levels as an adaptive response to hypoxia.

METHODS

This cross-sectional, hospital-based study utilized data from 645 Tibetan male patients with type 2 diabetes (T2D) between 2018 and 2020. Patients were divided into two groups based on Hb level (group 1: 12.0 ≤ Hb < 16.0 g/dL; group 2: Hb ≥ 16.0 g/dL). DR was diagnosed based on fundus photographs and fundus fluorescein angiography.

RESULTS

Among the study participants, 140 were diagnosed with DR. An inverse relationship was observed between Hb levels and the prevalence of DR. Each 1.0-g/dL increase in Hb concentration was associated with an 18% reduction in the prevalence of DR (95% confidence interval [CI]: 0.71-0.95). Multiple logistic regression analysis confirmed that patients with higher Hb levels had an adds ratio of 0.48 (95% CI, 0.29-0.79) for DR after adjusting for confounders, compared to those with lower Hb levels.

CONCLUSIONS

Our findings indicate that the inverse relationship between Hb levels and DR prevalence observed in lowland populations is also applicable to high-altitude individuals.