Difference in prevalence of diabetes and diabetic retinopathy among low-altitude dwellers vs. high-altitude dwellers in North India

Abstract

Background: Type-2 diabetes mellitus (DM) is one of the leading lifestyle-related chronic disease as its prevalence is expected to rise up to 24.0% in the world by 2025, which was only 6.3% in year 2003.
 Objective: To understand the high-altitude and low-altitude differentials for DM and diabetic retinopathy (DR) prevalence in a sub-Himalayan state of North India.
 Methods: The study was carried out in the Shahpur block of Kangra district (altitude 2,404 feet) and the Spiti block of Lahaul and Spiti district (altitude 12,500 feet) of Himachal Pradesh.
 Results: Among diabetics, the prevalence of DR was observed to be high (18.1%) in low landers and low (5.0%) in high landers. DM was more of a problem among low landers with a prevalence of 12.3% when compared to high landers (7.2%). Overall, the odd ratio of DR was twice as high (2.2; 95% confidence interval [CI]: 1.1-2.3) among patients with an unsatisfactory level of HbA1c (>8.0%) adjusted for gender, age group, smoking status and hypertension.
 Conclusion: Differential did exist, as DM and DR were significantly lower in high-altitude areas when compared to low-altitude areas.

High-Altitude Exposure and Diabetic Retinopathy: Unveiling the Impact and Mechanisms of Alleviation

“…Although some studies have suggested the beneficial effects of living at HA on glucose homeostasis, the relationship between HA and DR remains unclear owing to multiple factors and potential confounders, such as varying altitudes of the investigated population, duration of exposure to HA, genetic backgrounds, living conditions, dietary habits, and physiological adaptation. Table 1 summarizes the main findings of previous studies [9][10][11][12][13][14][15] that explored the impact of HA on DR. This review aimed to comprehensively explore the impact of HA exposure on DR, encompassing genetic adaptations, changes in glucose homeostasis, and related factors.…”