Bioelectrical characteristics of type 1 and type 2 diabetic subjects with reference to body water compartments.

Since bioelectrical characteristics correspond well to body water compartments, this study investigated bioelectrical differences between type 1 and type 2 diabetic subjects that could reflect differences in body water compartments. We investigated cross-sectionally 612 adult subjects, classified into 10 groups according to sex and disease (control, obese normal glucose tolerant, non-obese type 2 diabetes, obese type 2 diabetes, type 1 diabetes). Resistance (R), reactance (Xc) and phase angle (PA) were measured (800 microA - 50 kHz alternating current). The bioelectrical vector was obtained by plotting R and Xc normalized for height (ht), it is easily identified on the basis of the length (inversely related to the total body water, likewise R) and direction, given by the PA (inversely related to the extra-/intra-cellular water - ECW/ICW -). Results show that disease and sex had a significant (ANOVA: P<0.0001 for both F disease and F sex) and independent effect on both R/ht and Xc/ht; no difference was found between type 2 and type 1 diabetic groups. A bioelectrical vector with a lower PA characterized both type 2 and type 1 diabetic groups. An independent positive correlation between fasting plasma glucose and R/ht and a negative correlation between fasting plasma glucose and PA were observed. These findings suggest a non-different body water content and distribution between type 2 and type 1 diabetic subjects; the bioelectrical vector indicates a higher ECW/ICW in type 2 and type 1 diabetic compared to nondiabetic subjects.

Factors associated with autonomic nervous function in type 1 and type 2 diabetic subjects free of clinical manifestations of autonomic neuropathy.

Even though autonomic diabetic neuropathy is highly prevalent and a noted risk factor for cardiovascular morbidity and mortality, very little is known about factors associated with it. We carried out standard autonomic nervous system function tests by means of a computerized portable system on 55 diabetic patients (22 with type 1 diabetes, 33 with type 2 diabetes) who had no signs or symptoms of autonomic diabetic neuropathy and on 10 age- and sex-matched healthy control subjects. Test results of patients with type 1 diabetes did not differ significantly from those with type 2 diabetes. Of the clinical, metabolic, and anthropometric variables considered, only the duration of diabetes was inversely and independently correlated to deep breathing test scores (E:I ratio value of deep breathing 1.38-0.009. years of diabetes; R2 = 0.25). The duration of diabetes was inversely correlated to variations in orthostatic systolic blood pressure (r = -0.37, p < 0.01). The prevalence of diabetic retinopathy (score: 1 = no; 2 = yes) was significantly higher in the diabetic group with lower deep breathing values (1.8 +/- 0.3 vs 1.0 +/- 0.0; p < 0.01). The prevalence of ischemic electrocardiographic alterations (score: 1 = no; 2 = yes) was significantly higher in the diabetic group with a poorer orthostatic systolic blood pressure response (1.4 +/- 0.1 vs 1.2 +/- 0.1; p < 0.01). This study suggests that 1) autonomic neuropathy is correlated to disease duration; 2) type of diabetes, present level of metabolic compensation, and anthropometric characteristics do not seem correlated to this complication; 3) diabetic retinopathy and ischemic cardiopathy may be correlated to autonomic neuropathy.

Influences of obesity and weight loss on thyroid hormones. A 3-3.5-year follow-up study on obese subjects with surgical bilio-pancreatic by-pass.

The effects of changing body size, energy intake and substrate oxidation on serum T4, FT4, T3, FT3 and TSH were investigated in ten morbidly obese subjects (4 men/6 women; age: 37 +/- 6 years; BMI: 53.8 +/- 6.5 kg/m2; mean +/- SD) who had undergone a surgical bilio-pancreatic by-pass in order to reduce their body weight. The starting value of serum FT3 was inversely related to the BMI (r = -0.63; p < 0.05). After 1-3 months, all the subjects were losing weight and their intake of carbohydrates was almost negligible; at this time a significant reduction of T3 (-14.6%; p < 0.0001), T4 (-19.5%; p < 0.0001), and FT3 (-10.5%; p < 0.001) was observed. Nine to 16 months after surgery, all the subjects were still losing weight, although there was no carbohydrate restriction; T3, T4, and FT3 were lower than prior to surgery but were beginning to increase. Finally, after 36-42 months the body weight of all the patients had been stable for at least the previous six months (final BMI: 32.9 +/- 4.1) and their body composition, as assessed by bio-impedance, was almost normal; only the concentrations of FT3 proved to be significantly lower than the basal value (-11.2%; p < 0.03). The change in FT3 proved to be independently influenced by the degree of fat malabsorption but not by changes in any of the physical characteristics considered. All values were always in the normal range; FT4 and TSH did not change significantly during the whole period of study. The final concentrations of TSH proved to be independently related to the postabsorptive protein oxidation (g/24h) (TSH = 2.37-0.018* protein oxidation). These results would suggest that nutritional factors have some influence on the blood levels of thyroid hormones, especially of FT3, while the removal of obesity does not seem to have any independent effect in the long-run.