To determine whether some long-term diabetic patients with coexisting clinical osteoarthritis (OA) are less likely to develop diabetic retinopathy (DR) than other diabetic patients and whether there is a relation between the timing of the clinical OA onset and DR.
Retrospective case-control study of 85 osteoarthritic patients with 20 years or more diabetes (A/DM) control group and of 85 non-osteoarthritic diabetic patients (NoA/DM) matched for age, race, duration, and type of diabetes. Digital fundus photographs were graded for retinopathy in masked manner.
Glycosylated hemoglobin, hypertension, and smoking showed no significant difference. Twelve out of 85 patients (12.9%) in A/DM group developed proliferative diabetic retinopathy (PDR) whereas 79/85 (92.9%) NoA/DM patients developed PDR (P<0.001). The onset of OA symptoms was known in 80/85 of the A/D patients, including 47 patients with onset before or at the same year as DM and 33 patients with relative onset after the year of DM. All the 10 patients with PDR (10/33) developed OA subsequent to their initiation for diabetic treatment while 0/47 A/DM patients with the onset of osteoarthritic symptoms present before or the same year as their onset of diabetes developed PDR (P<0.001).
Our study suggests that in long-term DM, PDR was significantly associated with the absence of concomitant clinical OA. This observation was highly significant if the onset of the arthritis was the same year or before the onset of the diabetes.