Tracking of vitamin D status from childhood to early adulthood and its association with peak bone mass

Background: To our knowledge, there are few longitudinal studies of vitamin D status from childhood to early adulthood, and it is uncertain whether vitamin D predicts peak bone mass in young adults. Objectives: The purpose of this longitudinal study was to evaluate the long-term stability of vitamin D status from ages 6 to 20 y in healthy individuals and to study associations between serum 25-hydroxyvitamin D [25(OH)D] at different developmental stages and bone mass measured at age 20 y. Design: Participants were offspring of the Western Australian Pregnancy Cohort (Raine) study. Serum 25(OH)D was assessed at ages 6, 14, 17, and 20 y, and whole-body bone mineral content (BMC) and bone mineral density (BMD) were measured at age 20 y through the use of dual-energy X-ray absorptiometry (DXA). Our analysis included 821 participants (385 females) who had ≥3 serum 25(OH)D measures and DXA data. We used latent class growth analysis and identified 4 vitamin D status trajectories: consistently lower (n = 259), decreasing (n = 125), increasing (n = 138), and consistently higher (n = 299). Results: There were significant correlations between serum 25(OH)D concentrations at different time points in both sexes (r = 0.346–0.560, P \u3c 0.001), with stronger correlations at adjacent time points. In males, but not in females, serum 25(OH)D at ages 6, 17, and 20 y was positively associated with total-body BMC and BMD at age 20 y [covariate-adjusted increments of 40.7–53.9 g and 14.7–18.6 mg/cm2, respectively, per 25 nmol/L 25(OH)D]; when 25(OH)D at all 4 ages was included in the same model, the concentration at age 6 y remained significant. Males in the “consistently higher” trajectory had 3.2–3.4% higher total body BMC and BMD than those who were in the “consistently lower” trajectory, accounting for age and anthropometric and lifestyle factors. Conclusions: Within both sexes, there are moderate associations between vitamin D status measured in prepuberty, adolescence, and early adulthood. Vitamin D status in childhood is a significant predictor of peak bone mass in male but not female subjects

Developing a Self-Administered Questionnaire as a Guide to Consultations with Women Treated for Breast Cancer

Background. Health professionals, including general practitioners involved in followup of breast cancer patients, need to systematically assess opportunities to offer patients support with ongoing or new problems. Methods. A self-administered needs assessment questionnaire was developed with reference to a multidisciplinary team. Short, evidence-based, readable questions were emphasized, and questions were tested for face validity. The questions flowed across three domains: physical, social, and psychological. Content validity and user friendliness were assessed. Results. A final set of 30 questions was rated as easy to read and comprehend (Flesch Reading Ease score 65.8 and Flesch-Kincaid Grade Level 6.9). When piloted with twenty-one patients the self-administered questionnaire detected 121 items of unmet need encompassing all three domains. Conclusions. This self-administered questionnaire has the potential to assist in the holistic assessment of breast cancer patient after treatment. The clinical value of the self-administered questionnaire will need to be further tested before it can be widely adopted

Consistency of metabolic responses and appetite sensations under postabsorptive and postprandial conditions

The present study aimed to investigate the reliability of metabolic and subjective appetite responses under fasted conditions and following consumption of a cereal-based breakfast. Twelve healthy, physically active males completed two postabsorption (PA) and two postprandial (PP) trials in a randomised order. In PP trials a cereal based breakfast providing 1859 kJ of energy was consumed. Expired gas samples were used to estimate energy expenditure and fat oxidation and 100 mm visual analogue scales were used to determine appetite sensations at baseline and every 30 min for 120 min. Reliability was assessed using limits of agreement, coefficient of variation (CV), intraclass coefficient of correlation and 95% confidence limits of typical error. The limits of agreement and typical error were 292.0 and 105.5 kJ for total energy expenditure, 9.3 and 3.4 g for total fat oxidation and 22.9 and 8.3 mm for time-averaged AUC for hunger sensations, respectively over the 120 min period in the PP trial. The reliability of energy expenditure and appetite in the 2 h response to a cereal-based breakfast would suggest that an intervention requires a 211 kJ and 16.6 mm difference in total postprandial energy expenditure and time-averaged hunger AUC to be meaningful, fat oxidation would require a 6.7 g difference which may not be sensitive to most meal manipulations

Postprandial Energy Metabolism in the Regulation of Body Weight: Is there a Mechanistic Role for Dietary Calcium?

There has been much interest in the mechanisms by which calcium may attenuate weight gain or accelerate body fat loss. This review focuses on postprandial energy metabolism and indicates that dietary calcium increases whole body fat oxidation after single and multiple meals. There is, as yet, no conclusive evidence for a greater diet induced thermogenesis, an increased lipolysis or suppression of key lipogenic enzyme systems. There is however convincing evidence that higher calcium intakes promote a modest energy loss through increased fecal fat excretion. Overall, there is a role for dietary calcium in human energy metabolism. Future studies need to define threshold intakes for metabolic and gastrointestinal outcomes

Serum 25-hydroxyvitamin D concentrations and cardiometabolic risk factors in adolescents and young adults

Evidence associating serum 25-hydroxyvitamin D (25(OH)D) concentrations and cardiometabolic risk factors is inconsistent and studies have largely been conducted in adult populations. We examined the prospective associations between serum 25(OH)D concentrations and cardiometabolic risk factors from adolescence to young adulthood in the West Australian Pregnancy Cohort (Raine) Study. Serum 25(OH)D concentrations, BMI, homoeostasis model assessment for insulin resistance (HOMA-IR), TAG, HDL-cholesterol and systolic blood pressure (SBP) were measured at the 17-year (n 1015) and 20-year (n 1117) follow-ups. Hierarchical linear mixed models with maximum likelihood estimation were used to investigate associations between serum 25(OH)D concentrations and cardiometabolic risk factors, accounting for potential confounders. In males and females, respectively, mean serum 25(OH)D concentrations were 73·6 (sd 28·2) and 75·4 (sd 25·9) nmol/l at 17 years and 70·0 (sd 24·2) and 74·3 (sd 26·2) nmol/l at 20 years. Deseasonalised serum 25(OH)D3 concentrations were inversely associated with BMI (coefficient -0·01; 95 % CI -0·03, -0·003; P=0·014). No change over time was detected in the association for males; for females, the inverse association was stronger at 20 years compared with 17 years. Serum 25(OH)D concentrations were inversely associated with log-HOMA-IR (coefficient -0·002; 95 % CI -0·003, -0·001; P<0·001) and positively associated with log-TAG in females (coefficient 0·002; 95 % CI 0·0008, 0·004; P=0·003). These associations did not vary over time. There were no significant associations between serum 25(OH)D concentrations and HDL-cholesterol or SBP. Clinical trials in those with insufficient vitamin D status may be warranted to determine any beneficial effect of vitamin D supplementation on insulin resistance, while monitoring for any deleterious effect on TAG

Serum 25-hydroxyvitamin D concentrations and cardiometabolic risk factors in adolescents and young adults

Evidence associating serum 25-hydroxyvitamin D (25(OH)D) concentrations and cardiometabolic risk factors is inconsistent and studies have largely been conducted in adult populations. We examined the prospective associations between serum 25(OH)D concentrations and cardiometabolic risk factors from adolescence to young adulthood in the West Australian Pregnancy Cohort (Raine) Study. Serum 25(OH)D concentrations, BMI, homoeostasis model assessment for insulin resistance (HOMA-IR), TAG, HDL-cholesterol and systolic blood pressure (SBP) were measured at the 17-year (n 1015) and 20-year (n 1117) follow-ups. Hierarchical linear mixed models with maximum likelihood estimation were used to investigate associations between serum 25(OH)D concentrations and cardiometabolic risk factors, accounting for potential confounders. In males and females, respectively, mean serum 25(OH)D concentrations were 73·6 (sd 28·2) and 75·4 (sd 25·9) nmol/l at 17 years and 70·0 (sd 24·2) and 74·3 (sd 26·2) nmol/l at 20 years. Deseasonalised serum 25(OH)D3 concentrations were inversely associated with BMI (coefficient -0·01; 95 % CI -0·03, -0·003; P=0·014). No change over time was detected in the association for males; for females, the inverse association was stronger at 20 years compared with 17 years. Serum 25(OH)D concentrations were inversely associated with log-HOMA-IR (coefficient -0·002; 95 % CI -0·003, -0·001; P<0·001) and positively associated with log-TAG in females (coefficient 0·002; 95 % CI 0·0008, 0·004; P=0·003). These associations did not vary over time. There were no significant associations between serum 25(OH)D concentrations and HDL-cholesterol or SBP. Clinical trials in those with insufficient vitamin D status may be warranted to determine any beneficial effect of vitamin D supplementation on insulin resistance, while monitoring for any deleterious effect on TAG

Postprandial Energy Metabolism in the Regulation of Body Weight: Is there a Mechanistic Role for Dietary Calcium?

There has been much interest in the mechanisms by which calcium may attenuate weight gain or accelerate body fat loss. This review focuses on postprandial energy metabolism and indicates that dietary calcium increases whole body fat oxidation after single and multiple meals. There is, as yet, no conclusive evidence for a greater diet induced thermogenesis, an increased lipolysis or suppression of key lipogenic enzyme systems. There is however convincing evidence that higher calcium intakes promote a modest energy loss through increased fecal fat excretion. Overall, there is a role for dietary calcium in human energy metabolism. Future studies need to define threshold intakes for metabolic and gastrointestinal outcomes

Diet induced thermogenesis, fat oxidation and food intake following sequential meals: Influence of calcium and vitamin D

Background & aims: The mechanisms linking dietary calcium and vitamin D to body weight regulation require confirmation. Methods: Eleven subjects, aged (mean ± SEM) 54 ± 1.2 y and BMI 31 ± 2.4 kg/m2, participated in a randomised within-subject, sequential meal protocol comparing a low calcium trial (LCT) to an isoenergetic high calcium trial (HCT). Diet induced thermogenesis (DIT), fat oxidation rates (FOR), serum leptin, subjective feelings of hunger/satiety were measured at fasting and hourly over 8 h. Spontaneous food intake at a buffet and over the following 30 h was recorded. Postprandial responses, calculated as change (Δ) from baseline for each meal, were analysed by paired t-tests and 2 × 2 repeated measures ANOVA. Results: HCT resulted in lesser suppression of ΔFOR (p = 0.02) and a significantly greater DIT (p = 0.01). Further, the buffet to dinner interval was prolonged (p = 0. 083) and reported 24 h energy intake following this trial was significantly reduced (p = 0.017). ∆leptin following HCT but not LCT was negatively related to 24 h fat intake (r = −0.81, p = 0.016). Conclusions: Higher calcium and vitamin D intake at a breakfast meal acutely increased postprandial FOR and DIT over two successive meals, and reduced spontaneous energy intake in the subsequent 24 h period

Energy metabolism and the metabolic syndrome: Does a lower basal metabolic rate signal recovery following weight loss?

Aim: To determine whether basal metabolic rate (BMR) was causally related to MetS, and to study the role of gender in this relationship. Methods: Seventy-two Caucasian subjects (43 women, 29 men) had changes in basal metabolic rate (BMR), carbohydrate oxidation rate (COR), fat oxidation rate (FOR) and prevalence of the metabolic syndrome (MetS) assessed in response to weight loss. Results: There was a significant gender × MetS interaction in BMR at the start. Women with MetS had higher adjusted BMR, whilst men with MetS had lower adjusted BMR than their respective counterparts. Weight loss resulted in a significant decrease in fat mass (−5.2 ± 0.31 kg, p = 0.001), fat free mass (−2.3 ± 0.27 kg, p = 0.001), BMR (−549 ± 58 kJ/d, p = 0.001) and a decreased proportion of MetS (22/72, χ2 = 0.005). Subjects who recovered from MetS after weight loss (RMS) had ~250 kJ/d significantly lower adjusted BMR compared to those who were never MetS (NMS, p = 0.046) and those who still had MetS (MetS+, p = 0.047). Regression analysis showed that change (Δ) in BMR was best determined by Δglucose × gender interaction (r2 = 23%), ΔFOR (r2 = 20.3%), ΔCOR (r2 = 19.4%) and Δtriglycerides (r2 = 7.8%). Conclusions: There is a sexual dimorphism of BMR in MetS. Overall, the data support the notion that alterations in BMR may be central to the etiopathogenesis of MetS