To elucidate the role of adipose tissue glucose uptake in whole-body metabolism, sc and visceral adipose tissue glucose uptake and perfusion were measured in 10 nonobese and 10 age-matched obese men with positron emission tomography using [(18)F]-2-fluoro-2-deoxy-D-glucose, and [(15)O]-labeled water during normoglycemic hyperinsulinemia. Whole-body and skeletal muscle glucose uptake rates per kilogram were lower in obese than in nonobese subjects (P < 0.01). Compared with nonobese, the obese subjects had 67% lower abdominal sc and 58% lower visceral adipose tissue glucose uptake per kilogram of fat. In both groups, insulin stimulated glucose uptake per kilogram fat was significantly higher in visceral fat depots than in sc regions (P < 0.01). Both sc and visceral adipose tissue blood flow expressed per kilogram and minute was impaired in the obese subjects, compared with the nonobese (P < 0.05). Fat masses measured with magnetic resonance images were higher in obese than in nonobese individuals. If regional glucose uptake rates were expressed as per total fat mass, total glucose uptake rates per depot were similar in obese and nonobese subjects and represented 4.1% of whole-body glucose uptake in obese and 2.6% in nonobese subjects (P < 0.02 between the groups). In conclusion, insulin-stimulated glucose uptake per kilogram fat is higher in visceral than in sc adipose tissue. Glucose uptake and blood flow in adipose tissue exhibit insulin resistance in obesity, but because of the larger fat mass, adipose tissue does not seem to contribute substantially to the reduced insulin stimulated whole-body glucose uptake in obesity.

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Abstract. Laaksonen S, Voipio-Pulkki L-M, Erkinjuntti M, Asola M, Falck B (University Hospital, Turku, Finland). Does dialysis therapy improve autonomic and peripheral nervous system abnormalities in chronic uraemia? J Intern Med 2000; 248: 21±26.Objectives. Autonomic nervous system (ANS) dysfunction and peripheral neuropathy occur in patients with chronic renal insufficiency. Adequate renal replacement therapy should prevent development or correct these abnormalities. Design and subjects. We studied retrospectively ANS and peripheral neuropathy in 32 patients with chronic uraemia who received either haemodialysis (16) or peritoneal dialysis (16) therapy, and compared the observed dialysis efficiency with changes in neurological function. Methods. Heart rate variability (HRV) time domain indices and peripheral sensory nerve conduction studies were followed for a mean of 2.9 years. The adequacy of haemodialysis (HD) efficiency was estimated by Kt/V, an index of fractional urea clearance. Adequacy of continuous ambulatory peritoneal dialysis (CAPD) was estimated on the basis of the patient's wellbeing and nutritional status as excellent, satisfactory or poor. Based on observed changes in HRV time domain measures, the observations were divided in three subgroups: improved, unchanged or deteriorated. Results. The peripheral sensory nerve conduction studies were abnormal in 38% of the patients and did not change significantly during the study. Improvement in HRV time domain measures occurred in HD patients with mean Kt/V . 1.20 or in CAPD patients with satisfactory or excellent response to dialysis treatment. Values of Kt/V , 0.85 in HD patients were associated with progressive deterioration of autonomic neuropathy. Diabetic patients (n = 4) differed from others as their HRV was grossly abnormal and did not improve. Conclusions. The adequacy of haemodialysis is a predictor of improvement of cardiac autonomic nervous function in chronic uraemia. The same trend of improvement was seen also in CAPD patients.

End-stage renal disease (ESRD) is a significant global health problem that places a considerable burden on health care resources. The leading cause of death in ESRD patients is cardiovascular disease, which is often preceded by changes in cardiac geometry, including left ventricular hypertrophy (LVH). Treatments that result in regression of LVH have been shown to lead to better clinical outcomes. Globally, most ESRD patients receive conventional hemodialysis (CHD) 3 times per week, but mortality rates remain high and quality of life (QoL) is poor. Increasing the frequency of HD to 5 or 6 times per week, either as short daily HD (SDHD) or nocturnal HD (NHD), can improve QoL, reduce cardiovascular risk and prolong survival, compared with CHD. Improvements in these end points are likely driven by enhancements in fluid management, blood pressure control, mineral metabolism and left ventricular mass regression. From a practical standpoint, SDHD and NHD are best delivered at home. Barriers to adoption of home HD are chiefly modifiable, and may include lack of a care partner or family support, fear of cannulation and access disconnection, and uncertainty in one's ability to learn the procedures required to perform self-HD. On a positive note, substantial progress has been made to overcome these and other perceived barriers.