Body composition, adipokines, bone mineral density and bone remodeling markers in relation to IGF-1 levels in adults with Prader-Willi syndrome.

BACKGROUND: In patients with Prader-Willi syndrome (PWS) body composition is abnormal and alterations in appetite regulating factors, bone mineral density and insulin-like growth factor-1 (IGF-1) levels have been described. Studies in PWS adults are limited. In this study, we investigated body composition, appetite regulating peptides, bone mineral density and markers of bone remodeling in an adult PWS population. Furthermore, we investigated the association between these different parameters and IGF-1 levels because of the described similarities with growth hormone deficient patients. METHODS: In this cross-sectional observational cohort study in a university hospital setting we studied fifteen adult PWS patients. Anthropometric and metabolic parameters, IGF-1 levels, bone mineral density and bone metabolism were evaluated. The homeostasis model assessment of insulin resistance (HOMA2-IR) was calculated. Fourteen healthy siblings served as a control group for part of the measurements. RESULTS: In the adult PWS patients, height, fat free mass, IGF-1 and bone mineral content were significantly lower when compared to controls; body mass index (BMI), waist, waist-to-hip ratio and fat mass were higher. There was a high prevalence of osteopenia and osteoporosis in the PWS patients. Also, appetite regulating peptides and bone remodelling markers were aberrant when compared to reference values. Measurements of body composition were significantly correlated to appetite regulating peptides and high-sensitive C-reactive protein (hs-CRP), furthermore HOMA was correlated to BMI and adipokines. CONCLUSION: In adults with Prader-Willi syndrome alterations in body composition, adipokines, hs-CRP and bone mineral density were demonstrated but these were not associated with IGF-1 levels. Further investigations are warranted to gain more insight into the exact pathophysiology and the role of these alterations in the metabolic and cardiovascular complications seen in PWS, so these complications can be prevented or treated as early as possible.

Physical health problems in adults with Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is a genetic disorder which is characterized by severe hypotonia and feeding problems in early infancy. In later childhood and adolescence, this is followed by hyperphagia and extreme obesity if the diet is not strictly controlled. Data on physical health problems in adults with PWS are scarce. We report on the prevalence of physical health problems in a Dutch cohort of adults with PWS in relation to age, BMI, and genetic subtype. Participants (n = 102) were retrieved via the Dutch Prader-Willi Parent Association and through physicians specializing in persons with intellectual disabilities (ID). Details regarding physical health problem spanning the participants' lifespan were collected from caretakers through semi-structured interviews. Cardiovascular problems included diabetes mellitus, hypertension, and cerebrovascular accidents. Respiratory infections were frequent in adulthood. In males, cryptorchidism was almost universal, for which 28/48 males had a history of surgery, mostly orchidopexy. None of the women had a regular menstrual cycle. Sixteen individuals had a diagnosis of osteoporosis. Spinal deformation, hip dysplasia, and foot abnormalities were common. Skinpicking, leg edema, and erysipelas were frequent dermatological problems. The findings in our group support the notion that the prevalence of physical health problems is underestimated. This underscores the importance of developing monitoring programs which would help to recognize physical health problems at an early stage.

Does growth hormone replacement therapy reduce mortality in adults with growth hormone deficiency? Data from the Dutch National Registry of Growth Hormone Treatment in adults.

CONTEXT: Adults with GH deficiency (GHD) have a decreased life expectancy. The effect of GH treatment on mortality remains to be established. OBJECTIVE: This nationwide cohort study investigates the effect of GH treatment on all-cause and cause-specific mortality and analyzes patient characteristics influencing mortality in GHD adults. DESIGN, SETTING, AND PATIENTS: Patients in the Dutch National Registry of Growth Hormone Treatment in Adults were retrospectively monitored (1985-2009) and subdivided into treatment (n = 2229), primary (untreated, n = 109), and secondary control (partly treated, n = 356) groups. MAIN OUTCOME MEASURES: Standardized mortality ratios (SMR) were calculated for all-cause, malignancy, and cardiovascular disease (CVD) mortality. Expected mortality was obtained from cause, sex, calendar year, and age-specific death rates from national death and population counts. RESULTS: In the treatment group, 95 patients died compared to 74.6 expected [SMR 1.27 (95% confidence interval, 1.04-1.56)]. Mortality was higher in women than in men. After exclusion of high-risk patients, the SMR for CVD mortality remained increased in women. Mortality due to malignancies was not elevated. In the control groups mortality was not different from the background population. Univariate analyses demonstrated sex, GHD onset, age, and underlying diagnosis as influencing factors. CONCLUSIONS: GHD men receiving GH treatment have a mortality rate not different from the background population. In women, after exclusion of high-risk patients, mortality was not different from the background population except for CVD. Mortality due to malignancies was not elevated in adults receiving GH treatment. Next to gender, the heterogeneous etiology is of influence on mortality in GHD adults with GH treatment.

The association of serum insulin-like growth factor-I with mortality, cardiovascular disease, and cancer in the elderly: a population-based study.

CONTEXT: Numerous studies have investigated the effect of serum IGF-I concentration on aging and different aging-related diseases, e.g. cardiovascular disease (CVD) and cancer. Decreased as well as increased levels have been reported to be associated with reduced life expectancy in humans. OBJECTIVE: This study investigates the association of serum IGF-I concentration with all-cause and cause-specific mortality of community-dwelling older persons and the development of CVD and cancer. DESIGN, SETTING, AND PARTICIPANTS: Data were used from the Longitudinal Aging Study Amsterdam (LASA), an ongoing multidisciplinary cohort study in the general Dutch population of older persons (≥65 yr old) where serum IGF-I was measured (n = 1273). The mortality information was ascertained using the International Classification of Diseases, 10th revision, and the presence or absence of CVD and cancer by self-reports with a follow-up of 11.6 yr. MAIN OUTCOME MEASURE: We measured all-cause, CVD, and cancer mortality and nonfatal CVD and cancer. RESULTS: Fully adjusted Cox proportional hazards models demonstrated an increased risk of all-cause mortality for older persons with IGF-I values in the lowest quintile as compared to the middle quintile [hazard ratio (HR), 1.28; 95% confidence interval (CI), 1.01-1.63]. A more than 2-fold increased risk of CVD mortality was revealed for both low-normal (HR, 2.39; 95% CI, 1.22-4.66) and high-normal (HR, 2.03; 95% CI, 1.02-4.06) IGF-I values. Significant associations of serum IGF-I with nonfatal CVD and fatal and nonfatal cancer were not observed. CONCLUSIONS: Results suggest a U-shaped relationship between IGF-I level and mortality, with fatal CVD as the most critical outcome in community-dwelling older persons.

Serum insulin-like growth factor-I and body composition in community dwelling older people.

OBJECTIVES: The decline in the growth hormone/insulin-like growth factor-I (GH/IGF-I) axis during normal aging might be involved in the changes in body composition associated with increasing age. We conducted a study to investigate serum IGF-I levels across different age categories and a possible association between serum IGF-I and measurements of body composition in older people. DESIGN: A cross-sectional analysis of community dwelling older people, which participated in a large longitudinal cohort study (Longitudinal Aging Study Amsterdam). SUBJECTS: 1319 subjects, 644 men, mean age 75.6 +/- 6.6 years and 675 women, mean age 75.4 +/- 6.6 years. MAIN OUTCOME MEASUREMENTS: IGF-I, body mass index (BMI), waist, waist-hip ratio (WHR), fat mass, lean body mass and total bone mineral density. RESULTS: IGF-I levels were significantly lower in the highest age categories. BMI and biceps skinfold measurements were lower in the lowest IGF-I quartile in men aged > or =75.5 years. In men with a low total physical activity score (<131 min/day), BMI, WHR and skinfolds were significantly lower in the lowest IGF-I quartile. In women with a high total physical activity score (>174 min/day), WHR was lower in the lowest IGF-I quartiles. CONCLUSION: In this large cohort of community dwelling older people, we observed lower serum IGF-I levels in the higher age categories. A low serum IGF-I was associated with significantly lower measurements of body composition, such as BMI, skinfolds and WHR. These results do not support previous findings that high IGF-I levels are favourable for a healthy body composition in community dwelling older people.

Cognition in the adult with childhood-onset GH deficiency.

The GH/IGF1 axis may play an important role in cognitive function. This theory is supported by the finding that both GH and IGF1 receptors are located in several brain areas such as the hippocampus, a brain area that is known to play an essential role in cognitive processes, especially memory and learning. However, the exact mechanism by which the GH/IGF1 axis influences the cognitive functions is still unknown. Furthermore, little is known about the cognition in adults with both childhood-onset and adult-onset GH deficiency (CO-GHD and AO-GHD). Recent data indicate that cognitive function, particularly attention and memory, in adults with GHD might be impaired. To date, only a limited number of studies have been conducted to study the effects of GH replacement therapy on cognitive function in adults with GHD. In this paper, the results of studies on cognitive functioning in GHD patients, in particular the results of the studies performed in adults with CO-GHD, and the effects of GH replacement therapy in these patients, will be discussed.

Effects of the noradrenergic agonist clonidine on temporal and spatial attention.

RATIONALE: Recent theories posit an important role for the noradrenergic system in attentional selection in the temporal domain. In contrast, the spatially diffuse topographical projections of the noradrenergic system are inconsistent with a direct role in spatial selection. OBJECTIVES: To test the hypotheses that pharmacological attenuation of central noradrenergic activity should (1) impair performance on the attentional blink task, a task requiring the selection of targets in a rapid serial visual stream of stimuli; and (2) leave intact the efficiency of the search for a target in a two-dimensional visuospatial stimulus array. MATERIALS AND METHODS: Thirty-two healthy adult human subjects performed an attentional blink task and a visual search task in a double-blind, placebo-controlled, between-subject study investigating the effects of the alpha2 adrenoceptor agonist clonidine (150 microg, oral dose). RESULTS: No differential effects of clonidine vs placebo were found on the attentional blink performance. Clonidine slowed overall reaction times in the visual search task but did not impair the efficiency of the visual search. CONCLUSIONS: The attentional blink results are inconsistent with recent theories about the role of the noradrenergic system in temporal filtering and in mediating the attentional blink. This discrepancy between theory and data is discussed in detail. The visual search results, in combination with previous findings, suggest that the noradrenergic system is not directly involved in spatial attention processes but instead can modulate these processes in an indirect fashion.