Bone mineral density in patients with growth hormone deficiency: does a gender difference exist?

OBJECTIVE: The aim of the study was to clarify whether a gender difference exists with respect to bone mineral density (BMD) and bone mineral content (BMC) in adult patients with growth hormone deficiency (GHD). DESIGN: A case-control design. METHODS: Blood sampling for measurements of calcium, phosphate, creatinine, PTH, vitamin D, IGF-1, markers of bone formation and bone resorption, and dual energy X-ray absorptiometry (DEXA), to determine BMD and BMC of the lumbar spine, hip, distal arm and total body, were performed in 34 patients with GHD (19 females) and 34 sex-, age- and weight-matched healthy control subjects. The patients were well substituted on all pituitary axes, apart from GH. RESULTS: GH-deficient males had significantly lower BMD in the lumbar spine (P = 0.02), hip (P = 0.01) and total body (P = 0.003) than healthy males while GH-deficient females compared to healthy females had identical BMD values at all regions. This gender difference was even more obvious when BMD values were expressed as Z-scores or as three-dimensional BMD of the total body. The bone formation and bone resorption markers, as well as calcium and vitamin D, were all at the same levels in GH-deficient and healthy males, indicating identical bone turnover. The GH-deficient females, however, had significantly lower levels of bone markers compared to healthy females, indicating a reduced bone turnover. Oestrogen substitution of the GH-deficient females could explain this difference. CONCLUSIONS: Compared to healthy control subjects GH-deficient males had, in contrast to GH-deficient females, significantly reduced BMD and BMC. This obvious gender difference seems to be caused by the oestrogen substitution given to the females, compensating for the lack of GH, an effect testosterone does not seem to possess.     

Is leptin a significant predictor of bone mineral density in postmenopausal Turkish women?

The objective of the present study was to investigate the relationship between leptin and bone mineral density in postmenopausal Turkish women. A total of 122 healthy postmenopausal women were enrolled in this cross-sectional study. Blood samples were obtained for analysis of serum leptin. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry at the lumbar spine, femoral neck and trochanter on the same day. Leptin levels was significantly correlated with BMD of L(1-4) (P = 0.04), but not of femoral neck (P = 0.13), and trochanter (P = 0.39). However, Z scores of L(1-4) (P = 0.009), femur neck (P = 0.009), and femur trochanter (P = 0.025) were positively correlated with leptin levels. In multiple linear regression analysis, leptin was not found to be a statistically significant independent predictor for BMD. Leptin was associated with BMD and Z scores at various body sites; however, it was not an independent predictor of BMD.     

Coagulation and metastasis: what does the experimental literature tell us?

Inhibition of coagulation greatly limits cancer metastasis in many experimental models. Cancer cells trigger coagulation, through expression of tissue factor or P‐selectin ligands that have correlated with worse prognosis in human clinical studies. Cancer cells also affect coagulation through expression of thrombin and release of microparticles that augment coagulation. In the cancer‐bearing host, coagulation facilitates tumour progression through release of platelet granule contents, inhibition of Natural Killer cells and recruitment of macrophages. We are revisiting this literature in the light of recent studies in which treatment of clinical cohorts with anticoagulant drugs led to diminished metastasis.     

The observed global warming record: what does it tell us?

Global, near-surface temperature data sets and their derivations are discussed, and differences between the Jones and Intergovernmental Panel on Climate Change data sets are explained. Global-mean temperature changes are then interpreted in terms of anthropogenic forcing influences and natural variability. The inclusion of aerosol forcing improves the fit between modeled and observed changes but does not improve the agreement between the implied climate sensitivity value and the standard model-based range of 1.5-4.5 degrees C equilibrium warming for a CO2 doubling. The implied sensitivity goes from below the model-based range of estimates to substantially above this range. The addition of a solar forcing effect further improves the fit and brings the best-fit sensitivity into the middle of the model-based range. Consistency is further improved when internally generated changes are considered. This consistency, however, hides many uncertainties that surround observed data/model comparisons. These uncertainties make it impossible currently to use observed global-scale temperature changes to narrow the uncertainty range in the climate sensitivity below that estimated directly from climate models.     

Beyond bone mineral density: can existing clinical risk assessment instruments identify women at increased risk of osteoporosis?

OBJECTIVE: Although osteoporosis and fragility fracture are common amongst postmenopausal women, the extent of risk varies, and measurement of bone mineral density (BMD) is the standard tool used to diagnose and assess fracture risk. Rates of diagnosis remain relatively low, and several groups have developed instruments to help identify individuals who would most benefit from BMD testing. In this paper, we review and compare the performance of these instruments to identify those most useful in the primary care setting. DESIGN: Review of screening instruments comprised osteoporosis clinical risk factors and comparison of the sensitivity and specificity of these algorithms. RESULTS: Validated instruments have varying complexity, but similar sensitivity and specificity for identifying individuals who are likely to have low BMD. The area under the receiver operating characteristic curve ranges from 0.75 (SOFSURF) to 0.81 (SCORE). The simplest of the instruments (OST) uses only age and weight and has an AUC of 0.79. CONCLUSIONS: The Osteoporosis Self-assessment Tool, the simplest of the instruments, performs as well as more complex tools and, because of its simplicity, may be the most useful means for the busy clinician to identify postmenopausal women who would most benefit from BMD testing.     

Seasonality of tuberculosis in India: is it real and what does it tell us?

India has a third of the world's tuberculosis cases. Large-scale expansion of a national programme in 1998 has allowed for population-based analyses of data from tuberculosis registries. We assessed seasonal trends using quarterly reports from districts with stable tuberculosis control programmes (population 115 million). In northern India, tuberculosis diagnoses peaked between April and June, and reached a nadir between October and December, whereas no seasonality was reported in the south. Overall, rates of new smear-positive tuberculosis cases were 57 per 100000 population in peak seasons versus 46 per 100000 in trough seasons. General health-seeking behaviour artifact was ruled out. Seasonality was highest in paediatric cases, suggesting variation in recent transmission.