Peripheral adiposity in relation to offspring birth size in women with and without gestational diabetes: preliminary data.

OBJECTIVE: To document the relationship between maternal body composition parameters and offspring anthropometric measurements. METHODS: A prospective sample of 48 pregnant women with either gestational diabetes (GDM, n=21) or normal glucose tolerance (NGT, n=27) was studied. Maternal weight, hip circumference and skinfold thicknesses were obtained at 32 weeks of gestation. Offspring length and weight, as well as cranial and thoracic perimeters were obtained at birth. RESULTS: Reported maternal pregravid BMI correlated with offspring thoracic perimeter (ρ=0.52, P<0.05) and tended to correlate with birth weight (ρ=0.41, P=0.07). There were significant correlations between hip circumference and pregravid BMI, and with biceps, triceps, subscapular, thigh and total sum of skinfold thicknesses (ρ=0.53-0.75, all P<0.01). Hip circumference also correlated with offspring length (ρ=0.61), weight (ρ=0.75) and thoracic perimeter (ρ=0.60, all P<0.05). Maternal hip circumference was an independent and significant predictor of offspring weight, explaining 14.1% of the observed variance (P<0.05). CONCLUSION: In a sample of women with and without GDM, maternal hip circumference was strongly related to other body composition estimates and was also predictive of offspring size measurements at birth.

The Barriers to Physical Activity in Type 1 Diabetes (BAPAD-1) scale: predictive validity and reliability.

AIM: Perceived barriers are one determinant of physical activity. Depending on the study population, these barriers can vary. The aim of this study was to assess the reliability and predictive validity of the 'Barriers to Physical Activity in Type 1 Diabetes' (BAPAD-1) scale, developed by Dubé et al. METHODS: A total of 77 adults (48% women; age: 43.5±10.4; body mass index: 25.2±4.3kg/m(2); HbA(1c): 7.6±1.3%) with type 1 diabetes completed the questionnaire and an evaluation of their physical activity using an accelerometer (8.4±1.2 days) and cardiorespiratory fitness assessment (VO(2)(peak)). To evaluate the temporal stability of the questionnaire, a subgroup of 17 participants answered the BAPAD-1 scale on both visits required by the protocol (10±4 days). RESULTS: The BAPAD-1 scale showed good internal validity with an inter-items correlation coefficient (Cronbach's correlation) of 0.85. The intraclass correlation coefficient for the two times the scales were completed was 0.80. The BAPAD-1 score was negatively correlated with both physical activity energy expenditure (r=-0.25; P=0.03) and VO(2)(peak) adjusted for gender and age (r=-0.27; P=0.02). CONCLUSION: The BAPAD-1 scale is a reliable and valid tool for assessing salient barriers to physical activity. In future, this scale could be used to describe the factors accounting for physical activity, and for planning interventions aimed at promoting physical activity among adults with type 1 diabetes.

Relationship of mid-thigh adiposity to the metabolic syndrome in postmenopausal women.

BACKGROUND: In postmenopausal women, a population at risk for the metabolic syndrome, the relative contribution of central fat versus peripheral muscle fat to the metabolic risk profile is unknown. This study explored the relationship between muscle fat infiltration derived from computed tomography (CT) scans and metabolic syndrome. METHODS: Mid-thigh CT scans measured the surface of muscle with low attenuation (LAMS) [0-34 Hounsfield units (HU)], which represented the specific component of fat-rich muscle. Insulin sensitivity was evaluated by an euglycemic-hyperinsulinemic clamp. National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria were used to determine the presence of the metabolic syndrome. RESULTS: A total of 103 postmenopausal women were studied. Metabolic syndrome was found in 43 women with significantly higher levels of abdominal adiposity, higher LAMS (27 +/- 8 vs. 23 +/- 7 cm(2)), and lower insulin sensitivity compared to those without the metabolic syndrome. Women with higher levels of LAMS presented higher metabolic risk features such as higher blood pressure, abdominal adiposity, inflammatory markers, and blood lipid levels. LAMS and visceral adipose tissue correlated significantly with the presence of metabolic syndrome, but these relationships were lost when LAMS was adjusted for visceral adipose tissue but not when visceral adipose tissue was adjusted for LAMS. CONCLUSIONS: These results suggest that postmenopausal women who present with metabolic syndrome had increased fat-rich mid-thigh muscle. Moreover, women with more fat-rich muscle had many features of the metabolic syndrome. These relations were weakened when visceral adipose tissue was taken into account suggesting that LAMS may play a relatively smaller role, compared to VAT, in the contribution to the metabolic syndrome.

Substrate source utilization during moderate intensity exercise with glucose ingestion in Type 1 diabetic patients.

Substrate oxidation and the respective contributions of exogenous glucose, glucose released from the liver, and muscle glycogen oxidation were measured by indirect respiratory calorimetry combined with tracer technique in eight control subjects and eight diabetic patients (5 men and 3 women in both groups) of similar age, height, body mass, and maximal oxygen uptake, over a 60-min exercise period on cycle ergometer at 50.8% (SD 4.0) maximal oxygen uptake [131.0 W (SD 38.2)]. The subjects and patients ingested a breakfast (containing approximately 80 g of carbohydrates) 3 h before and 30 g of glucose (labeled with 13C) 15 min before the beginning of exercise. The diabetic patients also received their usual insulin dose [Humalog = 9.1 U (SD 0.9); Humulin N = 13.9 U (SD 4.4)] immediately before the breakfast. Over the last 30 min of exercise, the oxidation of carbohydrate [1.32 g/min (SD 0.48) and 1.42 g/min (SD 0.63)] and fat [0.33 g/min (SD 0.10) and 0.30 g/min (SD 0.10)] and their contribution to the energy yield were not significantly different in the control subjects and diabetic patients. Exogenous glucose oxidation was also not significantly different in the control subjects and diabetic patients [6.3 g/30 min (SD 1.3) and 5.2 g/30 min (SD 1.6), respectively]. In contrast, the oxidation of plasma glucose and oxidation of glucose released from the liver were significantly lower in the diabetic patients than in control subjects [14.5 g/30 min (SD 4.3) and 9.3 g/30 min (SD 2.8) vs. 27.9 g/30 min (SD 13.3) and 21.6 g/30 min (SD 12.8), respectively], whereas that of muscle glycogen was significantly higher [28.1 g/30 min (SD 15.5) vs. 11.6 g/30 min (SD 8.1)]. These data indicate that, compared with control subjects, in diabetic patients fed glucose before exercise, substrate oxidation and exogenous glucose oxidation overall are similar but plasma glucose oxidation is lower; this is associated with a compensatory higher utilization of muscle glycogen.

Muscle adiposity and body fat distribution in type 1 and type 2 diabetes: varying relationships according to diabetes type.

OBJECTIVE: To compare the relationships between markers of total and regional adiposity with muscle fat infiltration in type 1 diabetic and type 2 diabetic subjects and their respective nondiabetic controls, and to document these relationships in type 1 diabetic subjects. DESIGN: Cross-sectional study. SUBJECTS: In total, 86 healthy, with type 1 diabetes, type 2 diabetes or control subjects. Each diabetic group was matched for age, sex and body mass index with its respective nondiabetic control group. MEASUREMENTS: Measures of body composition (hydrodensitometry), fat distribution (waist circumference, abdominal and mid-thigh computed tomography scans) and blood lipid profiles were assessed. RESULTS: Low attenuation mid-thigh muscle surface correlated similarly with markers of adiposity and body composition in all groups, regardless of diabetes status, except for visceral adipose tissue and waist circumference. Indeed, relationships between visceral adiposity and muscle adiposity were significantly stronger in type 2 vs type 1 diabetic subjects (P<0.05 for comparison of slopes). In addition, in well-controlled type 1 diabetic subjects (mean HbA(1c) of 6.8%), daily insulin requirements tended to correlate with low attenuation mid-thigh muscle surface, a specific component of fat-rich muscle (r=0.36, P=0.08), but not with glycemic control (HbA(1c)). CONCLUSION: This study suggests that the relationship of central adiposity and muscle adiposity is modulated by diabetes status and is stronger in the insulin resistant diabetes type (type 2 diabetes). In well-controlled nonobese type 1 diabetic subjects, the relationship between muscle fat accumulation and insulin sensitivity was also maintained.

Is early and late post-meal exercise so different in type 1 diabetic lispro users?

To compare blood glucose (BG) responses during a 60 min moderate intensity exercise session performed in early or late postprandial periods. Nine generally well-controlled (HbA(1c): 7.3+/-0.1%) type 1 diabetic patients performed, at least one week apart, two exercise sessions, 60 (early exercise) and 180 min (late exercise) after a standardized breakfast. All subjects were using Humulin N (N) and Humalog (Lispro, LI) insulin. During exercise, the overall decrease in BG was 4.8+/-0.6 mmol/l and 3.6+/-0.8 mmol/l in early and late exercise, respectively (P=0.051). To prevent hypoglycemia, a dextrose infusion was initiated when BG reached 5 mmol/l. The quantity of dextrose infused was 6.2+/-3.0 g and 10.5+/-3.2g in early and late exercise, respectively (NS). The time free of dextrose infusion during exercise was 41.2+/-7.8 min and 31.7+/-7.5 min in early and late exercise, respectively (NS). In N-LI users, overall drop in BG during exercise tends to be greater in the early postprandial period. However, early and late exercise present similar quantity of dextrose infused and time free of dextrose infusion. Consequently, the similar risk of exercise-induced hypoglycemia suggests similar precautions in either exercise times.

Physical activity barriers in diabetes: development and validation of a new scale.

To develop and validate a questionnaire measuring perceived Barriers to Physical Activity in Diabetes (type 1) or BAPAD1. Initially, an open-ended questionnaire was filled by 36 patients. The modal accessible beliefs obtained on this pilot study were analysed and a scale composed of 12 items (BAPAD1) was developed and validated. Seventy-four type 1 diabetic patients filled the BAPAD1 scale. Cronbach alpha coefficient was 0.85 and the correlation between the test-retest scores was 0.84, both indicating adequate reliability of the barriers scale. Each item of BAPAD1 scale displayed very good item characteristic curve except for item 12, which was withdrawn. The test reliability curve indicated that the BAPAD1 scale is informative (value>or=0.82) at all levels of perceived barriers toward physical activity. Moreover, among diabetic-related items, the risk of hypoglycemia showed a particularly good item characteristic curve. In summary, the BAPAD1 scale presents excellent psychometric proprieties and among diabetic-related items, the risk of hypoglycemia should be considered as a significant target to overcome in order to increase physical activity. This new validated tool should be useful in identifying the most salient barriers toward the practice of physical activity and thus, permit more focused intervention in order to overcome those barriers.