The relationship between serum IGF-1, handgrip strength, physical performance and falls in elderly men and women.

OBJECTIVE: Human aging is accompanied by a decrease in growth hormone secretion and serum insulin-like growth factor (IGF)-1 levels. Also, loss of muscle mass and strength and impairment of physical performance, ending in a state of frailty, are seen in elderly. We aimed to investigate whether handgrip strength, physical performance and recurrent falls are related to serum IGF-1 levels in community-dwelling elderly. DESIGN: Observational cohort study (cross-sectional and prospective). METHODS: We studied the association between IGF-1 and handgrip strength, physical performance and falls in participants of the Longitudinal Aging Study Amsterdam. A total of 1292 participants were included (633 men, 659 women). Serum IGF-1 levels were divided into quartiles (IGF-1-Q1 to IGF-1-Q4). Data on falls were collected prospectively for a period of 3 years. All analyses were stratified for age and physical activity and adjusted for relevant confounders. RESULTS: Men with a low physical activity score in IGF-1-Q1 and IGF-1-Q2 of the younger age group had a lower handgrip strength compared to IGF-1-Q4. In younger more active males in IGF-1-Q2 physical performance was worse. Recurrent fallers were less prevalent in older, low active males with low IGF-1 levels. In females, recurrent fallers were more prevalent in older, more active females in IGF-1-Q2. IGF-1 quartile may predict changes in handgrip strength and physical performance in men and women. CONCLUSIONS: Our results indicate that lower IGF-1 levels are associated with lower handgrip strength and worse physical performance, but less recurrent fallers especially in men. Associations were often more robust in IGF-1-Q2. Future studies on this topic are desirable.

Acute and short-term effects of caloric restriction on metabolic profile and brain activation in obese, postmenopausal women.

OBJECTIVE: Early anthropometric and metabolic changes during a caloric-restricted diet in obese postmenopausal women and correlations between these factors with activity in brain areas involved in processing of visual food related stimuli were investigated. SUBJECTS AND METHODS: An 8-week prospective intervention study of 18 healthy postmenopausal women, with a body mass index of 30-35 kg m-2. The first 2 weeks subjects were on an isocaloric diet and 4 weeks on a 1000 kcal restricted diet followed by 2 weeks on an isocaloric diet. Anthropometric and laboratory analyses were performed weekly during the isocaloric diet and three times a week during the caloric-restricted diet. Functional magnetic resonance imaging scans were obtained before and after the caloric restriction in four separate sessions (fasting or sated). Generalized Estimating Equations analysis was used for data analysis. RESULTS: A mean weight loss of 4.2±0.5 kg (4.8%) and a 4.2±0.4 cm decline in waist circumference were achieved. In the first week of caloric restriction, triglyceride, leptin, resistin and adiponectin levels as well as systolic blood pressure decreased and insulin-like growth factor-binding protein 1 levels increased. During and after weight loss, a significant increase in ghrelin levels was observed. Before weight loss, increased activation of the right amygdala was seen in response to food stimuli, and free fatty acids and glucose correlated with activity in various areas involved in food reward processing. After weight loss, fasting ghrelin and sated leptin levels correlated with activity in these areas. CONCLUSIONS: Already in the first week of caloric restriction in obese postmenopausal women, various favourable metabolic changes occur before clinically relevant weight loss is achieved. Activity in the amygdala region and correlations of metabolic factors with activity in brain areas involved in food reward processing differ substantially before and after weight loss.

The GH/IGF-I axis and pituitary function and size in adults with Prader-Willi syndrome.

BACKGROUND: In adults with Prader-Willi syndrome (PWS), limited information is available about pituitary function, more specifically the prevalence of growth hormone deficiency (GHD). The aim of this study was to gain more insight into endocrine function in PWS adults, with emphasis on GH secretion. METHODS: 15 randomly selected adult PWS individuals were included and 14 healthy brothers and sisters served as a control group. Main outcome measures were IGF-I, IGFBP-3 and peak GH level after a combined GHRH-arginine test. Other pituitary hormone deficits are diagnosed based on serum levels of the concerning hormones. The size of the pituitary gland was measured on MRI images. RESULTS: In PWS adults, IGF-I levels were low and IGFBP-3 levels normal when compared to healthy controls. GHD was diagnosed in 8-38% of the PWS patients, depending on the criteria used. Hypogonadism was present in 87% of the patients. Hypothyroidism and adrenal insufficiency could also be demonstrated. Anterior pituitary size was lower in PWS individuals when compared to healthy controls. CONCLUSION: In this study, pituitary hormone deficiencies are demonstrated in a considerable number of adults with PWS, hypogonadism and GHD being most prominent. Furthermore, the anterior pituitary is smaller in comparison with healthy controls.

Dutch National Registry of GH Treatment in Adults: patient characteristics and diagnostic test procedures.

OBJECTIVE: The Dutch National Registry of GH Treatment in Adults was established in 1998 as an initiative of the Ministry of Health. The main goals were to gain more insight into long-term efficacy, safety, and costs of GH therapy (GHT) in adult GH-deficient (GHD) patients in The Netherlands. METHODS: Baseline patient characteristics and diagnostic test procedures were evaluated. RESULTS: Until January 2009 in roughly 10 years, 2891 patients (1475 men and 1416 women, mean age 43.5±16.5 years) were registered. GHD was of childhood-onset (CO) in over 20% of the patients and of isolated in 11%. The most common causes of GHD were pituitary tumors and/or their treatment, craniopharyngiomas, and idiopathic GHD. In 85% of the patients, a GH stimulation test was performed, in the majority an insulin tolerance test (ITT) (49%) or a combined GHRH-arginine test (25%). In 12% of the patients, IGF1 levels were ≤-2 s.d. combined with two or more additional pituitary hormone deficits, and in 2%, it concerned patients with CO-GHD continuing GHT in adulthood. Over the years, the test of first choice shifted from ITT toward GHRH-arginine test. CONCLUSION: Nearly, 2900 patients were included in the nationwide surveillance database of the Dutch National Registry of GH Treatment in Adults until January 2009. Baseline patient characteristics are comparable to that reported previously. In 85% of these patients, the diagnosis of GHD was established by provocative testing, particularly an ITT or a combined GHRH-arginine test, with an evident increase in the percentage of GHRH-arginine tests being performed in the last years.

The relationship between IGF-I concentration, cognitive function and quality of life in adults with Prader-Willi syndrome.

Mental retardation is one of the clinical characteristics of Prader-Willi syndrome (PWS) and in part of the patients growth hormone deficiency is demonstrable. Cognitive function seems to be influenced by insulin-like growth factor I (IGF-I); however, little is known about cognitive function in relation to IGF-I levels in PWS adults. The aim of the present study was to evaluate cognitive function in adult PWS patients in comparison to healthy siblings and to investigate whether there is a correlation between cognitive function and IGF-I levels. Anthropometric measurements, IGF-I levels, quality of life (QoL), Appetite Assessment Score, IQ (GIT and Raven) and cognitive function (by four subtests of the Cambridge Neuropsychological Automated Testing Battery, CANTAB) were evaluated in PWS patients and their healthy siblings served as control group. PWS patients had significantly lower IGF-I levels, IQ and QoL when compared to controls. Reaction times were longer and performance was worse on CANTAB subtests in PWS adults. IGF-I on one hand and IQ, Appetite Assessment Score and cognitive performance on the other hand seem to be correlated in PWS patients. In conclusion, IGF-I levels, IQ and QoL are significantly lower in PWS subjects when compared to healthy siblings. In PWS adults, temporal as well as prefrontal cognitive functions are impaired. Higher IGF-I levels appear to be related to better intellectual skills and faster temporal memory processing in PWS patients.