Factor analysis of thermal and vibration thresholds in young patients with Type 1 diabetes mellitus O. Kalter-Leibovici*², G. Yosipovitch³, U. Gabbay*, D. Yarnitsky§ and M. Karp² Abstract Aims To identify factors that represent relationships among sets of interrelated thermal and vibration threshold variables and to ®nd clinical correlates that are signi®cantly associated with these factors. Methods Thermal and vibration perception thresholds were tested in the hands and feet of Type 1 diabetic patients treated in an outpatient clinic for juvenile-onset diabetes. Factor analysis was used to identify factors that represent relationships among sets of thermal and vibration threshold variables. Results One hundred and forty-eight patients (47.3% males, median current age 22.3 years and median duration of diabetes 11.4 years) were evaluated. Three factors explained 77% of the total variance: `hand sensation' factor, underlying cold, warmth and vibration perception thresholds in the hand; `foot sensation' factor, underlying the same sensory thresholds in the foot; and `heat-related pain' factor, underlying heat pain perception threshold in both limbs. The `foot sensation' factor was the only factor that signi®cantly correlated with diabetes-related variables (e.g. duration and cumulative glycaemic control of the disease) and concurrent diabetic microangiopathy. Male sex was associated with higher values of the `heat-related' factor, while the `hand sensation' factor did not correlate with any of the study variables. Conclusions The distribution of the various thermal and vibration threshold variables according to the three factors may point at length-dependent mechanism of axonal degeneration. Cold, warmth and vibration perception thresholds in the foot may be the only valuable psychophysical parameters in the evaluation of early sensory impairment associated with diabetes. Diabet. Med. 18, 213±217 (2001) Keywords diabetic neuropathy, factor analysis, glycaemic control, sensory thresholds, Type 1 diabetes mellitus Abbreviations DSDP, distal symmetric diabetic polyneuropathy; GHB, glycosylated haemoglobin; QST, quantitative sensory testing; UAER, urinary albumin excretion rate Introduction Sensory impairment is a hallmark of distal symmetric diabetic polyneuropathy (DSDP) and a major risk factor for foot ulceration and limb amputation among diabetic individuals [1,2]. The assessment of sensory impairment in DSDP includes quantitative sensory testing (QST) of vibration, thermal and pain perception thresholds at different body sites. Thus, QST may give rise to numerous results of sensory thresholds, while the pathophysiological and prognostic signi®cance of each individual threshold is unclear. *Gertner Institute for Epidemiology & Health- Policy Research, Sheba Medical Center, Tel- Hashomer, Sackler School Of Medicine, Tel-Aviv University, Tel-Aviv, Israel ²Institute for Endocrinology & Diabetes, Schneider Children's Medical Center of Israel, Petach-Tikva, Sackler School of Medicine Tel-Aviv. University, Tel-Aviv, Israel ³Department of Dermatology, Rabin Medical Center, Beilinson Campus, Petach-Tikva, Sackler School Of Medicine Tel-Aviv University, Tel-Aviv, Israel §Department of Neurology and Institute of Clinical Neurophysiology, Rambam Medical Center, Technion Medical School, Haifa, Israel Accepted 5 November 2000 Correspondence to: O. Kalter-Leibovici, Unit of Cardiovascular Epidemiology, Gertner Institute for Epidemiology & Health-Policy Research, Sheba Medical Center, Hashomer, 52621, Israel. ã 2001 Diabetes UK. Diabetic Medicine, 18, 213±217 213