Fracture risk prediction and the decision to treat low bone density.

BACKGROUND AND OBJECTIVES: In patients without a prevalent fracture, guidelines recommend initiating therapy based on a calculation of absolute fracture risk. Two common calculators are used in Australia - FRAX (Australia) and Garvan Fracture Risk Calculator (Garvan). The aim of this article is to examine whether the decision to treat with bone-preserving medication would be different depending on which calculator was used. METHOD: Data were entered into each calculator for hypothetical male and female patients, aged 50-85 years, with femoral neck t-scores from +3.0 to -3.0. RESULTS: Garvan consistently predicted a higher absolute fracture risk than FRAX (Australia). The discrepancy increased with increasing age and decreasing bone mineral density, and was most pronounced in the prediction of any fracture, but less so for hip fracture. DISCUSSION: The decision to prescribe osteoporosis medications for a patient on the basis of fracture risk may depend on which risk calculator is used. Differences in the calculator methods contribute to the discrepancy between them.

Clustering of metabolic and cardiovascular risk factors in the polycystic ovary syndrome: a principal component analysis.

CONTEXT: Polycystic ovary syndrome (PCOS) is a prevalent condition with heterogeneity of clinical features and cardiovascular risk factors that implies multiple aetiological factors and possible outcomes. OBJECTIVE: To reduce a set of correlated variables to a smaller number of uncorrelated and interpretable factors that may delineate subgroups within PCOS or suggest pathogenetic mechanisms. MATERIALS AND METHODS: We used principal component analysis (PCA) to examine the endocrine and cardiometabolic variables associated with PCOS defined by the National Institutes of Health (NIH) criteria. Data were retrieved from the database of a single clinical endocrinologist. We included women with PCOS (N = 378) who were not taking the oral contraceptive pill or other sex hormones, lipid lowering medication, metformin or other medication that could influence the variables of interest. PCA was performed retaining those factors with eigenvalues of at least 1.0. Varimax rotation was used to produce interpretable factors. RESULTS: We identified three principal components. In component 1, the dominant variables were homeostatic model assessment (HOMA) index, body mass index (BMI), high density lipoprotein (HDL) cholesterol and sex hormone binding globulin (SHBG); in component 2, systolic blood pressure, low density lipoprotein (LDL) cholesterol and triglycerides; in component 3, total testosterone and LH/FSH ratio. These components explained 37%, 13% and 11% of the variance in the PCOS cohort respectively. CONCLUSIONS: Multiple correlated variables from patients with PCOS can be reduced to three uncorrelated components characterised by insulin resistance, dyslipidaemia/hypertension or hyperandrogenaemia. Clustering of risk factors is consistent with different pathogenetic pathways within PCOS and/or differing cardiometabolic outcomes.

Vitamin D status and its predictive factors in pregnancy in 2 Australian populations.

BACKGROUND: High prevalence rates of suboptimal vitamin D levels have been observed in women who are not considered 'at risk'. The effect of behavioural factors such as sun exposure, attire, sunscreen use and vitamin D supplementation on vitamin D levels in pregnancy is unknown. AIM: To determine prevalence and predictive factors of suboptimal vitamin D levels in 2 antenatal clinics in Australia--Campbelltown, NSW and Canberra, ACT. METHODS: A cross-sectional study of pregnant women was performed with a survey of demographic and behavioural factors and a mid-pregnancy determination of maternal vitamin D levels. RESULTS: The prevalence of vitamin D deficiency (≤25 nmol/L) and insufficiency (26-50 nmol/L) was 35% in Canberra (n=100) and 25.7% in Campbelltown (n=101). The majority of participants with suboptimal D levels had vitamin D insufficiency. Among the vitamin D-deficient women, 38% were Caucasian. Skin exposure was the main behavioural determinant of vitamin D level in pregnancy in univariate analysis. Using pooled data ethnicity, season, BMI and use of vitamin D supplements were the main predictive factors of suboptimal vitamin D. Vitamin D supplementation at 500 IU/day was inadequate to prevent insufficiency. CONCLUSIONS: Behavioural factors were not as predictive as ethnicity, season and BMI. As most participants had one of the predictive risk factors for suboptimal vitamin D, a case could be made for universal supplementation with a higher dose of vitamin D in pregnancy and continued targeted screening of the women at highest risk of vitamin D deficiency.

Endocrine and metabolic aspects of the Wolfram syndrome.

Wolfram syndrome (WS), also known as DIDMOAD (Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy and Deafness), is a neurodegenerative disease with autosomal recessive inheritance with incomplete penetrance. DIDMOAD is a very rare disease with an estimated prevalence of 1 in 770,000 and it is believed to occur in 1 of 150 patients with juvenile-onset insulin-dependent diabetes mellitus. Additionally, WS may also present with different endocrine and metabolic abnormalities such as anterior and posterior pituitary gland dysfunction. This mini-review summarizes the variable presentation of WS and the need of screening for other metabolic and hormonal abnormalities, coexisting in this rare syndrome.