Association of insulin treatment versus oral hypoglycaemic agents with diabetic retinopathy and its severity in type 2 diabetes patients in Cameroon, sub-Saharan Africa

Abstract

Background: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease associated with multiple macro and microvascular complications, diabetic retinopathy (DR) being the commonest one. Recent literature has reported an increased risk of DR with insulin use. Methods:We carried out a cross-sectional study at the Ophthalmology Department of the Douala General Hospital (DGH) during a 2-year period to explore the association between insulin treatment and both DR and its severity as compared with oral hypoglycemic agents (OHAs) in Cameroonian T2DM patients aged ≥35 years, and who were all screened for DR through eye examination including exhaustive retinal evaluation.Results: In total, medical files of 134 T2DM patients were analyzed. The frequency of DR was 54.1% among patients on OHA and 73.9% among those on insulin treatment, giving an overall frequency of 57.5%. There were significantly more OHA treated patients than insulin treated patients (82.8% vs. 17.2%, P<0.001). As expected, both the OHA and insulin groups were comparable by age, sex, duration of diabetes, past history of hypertension, alcohol misuse, and current tobacco smoking. DR was almost significantly more frequent in T2DM patients under insulin regimen than in patients under OHA [73.9% vs. 54.1%; odds ratio (OR) 2.4; 95% confidence interval (CI), 0.9-6.6; P=0.06]. Proliferative diabetic retinopathy (PDR) was significantly more observed in insulin treated patients than in OHA treated patients (34.8% vs. 15.3%; OR 2.95; 95% CI, 1.1-8; P=0.035). Irrespective of staging, the frequency of diabetic macular edema (DME) was significantly higher in the insulin group than in the OHA group (43.5% vs.19.8%; OR 3.1; 95% CI, 1.2-8; P=0.019).Conclusions: Compared with OHA, insulin therapy may be associated with DR, DR severity and DME in these T2DM sub-Saharan African patients.

Diabetic Retinopathy and the Risk Factors in South Sudan: A Six Months Study

“…The prevalence of DR was 13%. This was the same as studies conducted in Ethiopia 13% [15] and similar to researches done in Oman 14.4% [16] but lower than results from Tanzania 27.9% [17], Saudi Arabia 36.4% [18], Malawi 50.1% [19] with Cameroon having the highest 54.1% and 73.9% [20]. These disparities especially within the African countries may be due to difference in the study methods used, demographical data, type of DM, duration of DM, culture, availability of the diabetic services in the studied communities and the health seeking behavior.…”

“…Other studies like in Sudan 1.7% [14], Nigeria 2% [12] had documented higher results than ours. Higher prevalence of PDR had being found in some African countries [20,23,24] to be associated with complications of DM. Global DME was 6.8% [21] which was similar to our study 7.4% but some studies [11] had shown a higher record 32.2%.…”

Effect of basal insulin supplement therapy on diabetic retinopathy in short‐duration type 2 diabetes: A one‐year randomized parallel‐group trial

“…The findings of an experimental animal study also suggested that insulin treatment benefited DR . However, some studies have suggested that insulin therapy could be harmful with regard to DR . These inconsistent results imply that the relationship between insulin treatment and DR is complicated.…”

“…[10][11][12][13][14] A systematic review revealed that insulin treatment can also reduce DR in T2D, although the reduction was not as marked as that in T1D. 15 The findings of an experimental animal study also suggested that insulin treatment benefited DR. 16 However, some studies have suggested that insulin therapy could be harmful with regard to DR. [2][3][4][5][6] These inconsistent results imply that the relationship between insulin treatment and DR is complicated. Indeed, numerous factors contribute to this relationship, such as the duration of diabetes, HbA1c, background treatment, complications, accompanying diseases, β-cell function, the timing and duration of insulin therapy, and the stage of DR. To the best of our knowledge, no investigation has compared the effects on DR of different regimens as subsequent therapies after intensive glycemic treatment.…”

The incidence of type 2 diabetes in patients presenting for bariatric metabolic surgery at a tertiary bariatric surgery centre in India

“…Similar Jingi AM et al, found in association of insulin treatment versus oral hypoglycaemic agents with diabetic retinopathy. 18…”