OBJECTIVES: The aim of this study was to evaluate the typical strategies of obese subjects during a sit-to-stand task (a typical daily living activity) and to assess the load conditions of hip, knee and ankle joints. DESIGN: Cross-sectional, controlled (obese patients vs controls) study on sit-to-stand movement analysis SUBJECTS: Ten adult young volunteers (®ve men and ®ve women, mean age 28, s.d. 3 y; mean BMI 22, s.d. 2.3 kgam 2 ) and 30 obese subjects 25 women and ®ve men, mean age 39.4, s.d. 13.7 y, mean BMI 40, s.d. 5.9 kgam 2 ) suffering from chronic lower back pain were analyzed in a sit-to-stand task (10 trials for each subject). MEASUREMENTS: Angle parameters carried out from a quantitative three-dimensional analysis of sit-to-stand (STS) movement, using an optoelectronic system. RESULTS: STS task in controls was characterized by a fully forward bending strategy of the trunk, while in obese patients at the beginning (®rst trial) of the STS task they limited the forward bending in order to protect the vertebral column. When fatigue increased during the execution of multiple STS tasks, the protection of the vertebral column was secondary to the execution of the task. In order to limit the muscle fatigue they increased the forward bending in order to decrease knee joint torque. DISCUSSION: The analysis of the strategy used by obese patients in STS task can be used in the design of future trials to assess the ef®cacy of rehabilitative treatment.

Little is known about body composition in Parkinson's disease (PD). We studied 35 patients (20 male, 15 female subjects; mean age 69.7+/-5.8 years) with advanced PD by anthropometry, dual-energy X-ray absorptiometry (DEXA), and serum 25-OH vitamin D measurement. Over 70% of patients had a disease duration of more than 4 years; all were on L-dopa treatment. Low levels of serum 25-OH vitamin D were present in 41% of the patients. The mean body mass index (BMI) was 25.3+/-4.3 kg/m(2) (range 17.1-37.3). Mid-arm muscle circumference was below the 10th percentile in 23%. For whole-body mean (+/-SD) bone mineral density, the T score was below -1 SD in 35% of patients, and the Z score was below -1 SD in 24%. Percent fat mass measured with DEXA was 30.6+/-11.4% (range 10.1-45.5) in the overall sample; it was 21.1+/-8.8% (range 10.1-30.4) in male subjects and 38.1+/-9.2% (range 25.8-45.5) in female subjects. We conclude that advanced-stage PD may show excess adiposity coexisting with depletion of lean body mass (sarcopenic obesity), in addition to decreased whole-body bone mineral density associated with low serum 25-OH vitamin D. A low level of physical activity and inadequate exposure to sunlight are likely to be among the putative causes.

Multicenter, independent, prospective, randomized controlled trial with level of evidence 1.

It has been suggested that reduced GH secretion in Prader-Willi syndrome (PWS) may simply reflect their excessive fat body mass. However, the GH response to standard provocative tests is significantly lower in PWS adults than obese controls with similar body mass index (BMI). Nevertheless, BMI is an inadequate measure of body composition, because PWS harbor a higher percentage of fat body mass (FM%) than simple obesity, under the same degree of weight excess. This study evaluated either the GH response to combined GHRH + arginine administration and the FM%, by DEXA, in 11 PWS adults (8 females, aged 20.1-41.1 years, BMI 43.6 +/- 1.8, FM% 53.0 +/- 1.5), in comparison to those obtained in 10 patients with essential obesity (8 females, aged 23.5-45.8 years), matched for BMI and FM% (42.9 +/- 0.4 and 51.5 +/- 1.0, respectively). Moreover, IGF-I levels were measured in both groups. The GH response to GHRH + arginine was significantly lower in PWS patients (GH peak 5.4 +/- 1.3 microg/L; area under the curve (AUC) 311.2 +/- 72.5 microg/L/hr) than obese controls (GH peak 21.0 +/- 4.1 microg/L, P < 0.005; AUC 1241.1 +/- 272.8 microg/L/hr; P < 0.01), as well as IGF-I values (110.5 +/- 16.7 microg/L vs. 242.1 +/- 31 microg/L, P < 0.005). The GHRH + arginine induced GH rise in patients with del15q11-q13 was significantly higher than subjects with UPD15 (GH peak 7.7 +/- 1.7 microg/L vs. 2.7 +/- 1.0 microg/L, P < 0.05; AUC 458.5 +/- 91.0 microg/L/hr vs. 134.4 +/- 46.0 microg/L/hr, P < 0.02). These findings suggested that stimulated GH levels are significantly lower in PWS adults when compared to obese controls and that GH response to GHRH + arginine is different in PWS individuals having separate genetic subtypes.