Incidence of Microvascular Complications in Type 1 Diabetic Subjects with Limited Joint Mobility: A 10-Year Prospective Study

Previous cross-sectional studies have shown a significant correlation between limited joint mobility (LJM) and the microvascular complications of Type 1 diabetes, but whether LJM precedes and, therefore, may be regarded as an early marker for complications is unknown. Twenty-two Type 1 diabetic patients (10 male/12 female; diabetes duration at follow-up 20.1 ± 1.3 (SEM) years) with LJM, and 22 subjects matched for age, sex, and duration of diabetes, without LJM were observed over a 10-year period. Both groups were free of retinopathy and negative for ‘dipstick’ proteinuria at baseline. After 10 years, of 22 patients with LJM, 10 had developed background and 3 proliferative retinopathy compared with 9 and 1 control subjects, respectively. Microalbuminuria (20 ≤ albumin excretion rate < 200 μg min⁻¹) was present in 3 and macroalbuminuria (albumin excretion rate ≥ 200 μg min⁻¹) in 2 of LJM patients compared with 6 and 1 control subjects, respectively. Ankle and toe vibration perception thresholds, HbA₁, mean HbA₁ (a mean of serial HbA₁ measurements obtained during the 10-year follow-up period), and arterial blood pressure did not differ between the two groups (p > 0.05). At 10-year review, 9 of the control subjects had developed LJM of whom 4 had retinopathy and 4 microalbuminuria. Thus, while LJM may be another ‘chronic complication’ of diabetes, its presence does not appear to predict those at increased risk of developing microvascular complications.