Endocrine Abstracts

Growth hormone (GH) and insulin like growth factor 1 (IGF-I) modulate and stimulate angiogenesis and endothelial function. Excess of GH, as in acromegaly, is associated with cardiovascular morbidity and mortality, which is reversible after normalization of IGF-I and GH. Diabetes mellitus (DM) is a common comorbidity in acromegaly, but the prevalence of diabetes retinopathy in patients with acromegaly is unknown. Also, the roles of GH and IGF-I in diabetes retinopathy are not fully understood. We examined retinal vessels of 26 patients with acromegaly at diagnosis and one year after initiated treatment compared to the retina of 13 healthy controls. Fundus photographs were analyzed for vessel tortuosity, branching points and optic nerve morphology by a computer assisted mapping system. Subjective analysis for diabetes retinopathy was performed in a masked fashion. At diagnosis one patient had type-1 DM, 6 patients had type-2 DM and 6 patients had impaired glucose tolerance. The prevalence of pre-proliferative diabetes retinopathy in the patients with acromegaly and DM was 43%. Independent of diabetic status patients with acromegaly had 34.3 [30.0;39.0] (Median [interquartile range]) branching points while healthy controls had 27.0 [24.0–29.0], P<0.001. No difference in tortuosity of arterioles and venules or optic disc morphology was observed. The high amount of branching points remained unchanged at 1-year follow-up. In conclusion, patients with acromegaly had increased number of retinal vascular branching points without altering macroscopic vessel morphology that remained unchanged although hormone levels normalized 1 year after treatment. The prevalence of diabetes retinopathy in our patients with acromegaly and diabetes seemed to be higher than in the general type-2 diabetic population in Sweden (28.6% in 2017) according to the Swedish National Diabetes Registry.