Novel Lipidomic Signature Associated With Metabolic Risk in Women With and Without Polycystic Ovary Syndrome

CONTEXT

Dyslipidemia is a feature of polycystic ovary syndrome (PCOS) and may augment metabolic dysfunction in this population.

OBJECTIVE

Using comprehensive lipidomic profiling and gold-standard metabolic measures, we examined whether distinct lipid biomarkers were associated with metabolic risk in women with and without PCOS.

METHODS

Using preexisting data and biobanked samples from 76 women (n = 42 with PCOS), we profiled > 700 lipid species by mass spectrometry. Lipids were compared between women with and without PCOS and correlated with direct measures of adiposity (dual x-ray absorptiometry and computed tomography) and insulin sensitivity (hyperinsulinemic-euglycemic clamp), as well as fasting insulin, HbA1c, and hormonal parameters (luteinizing and follicle-stimulating hormones; total and free testosterone; sex hormone-binding globulin [SHBG]; and free androgen index [FAI]). Multivariable linear regression was used with correction for multiple testing.

RESULTS

Despite finding no differences by PCOS status, lysophosphatidylinositol (LPI) species esterified with an 18:0 fatty acid were the strongest lipid species associated with all the metabolic risk factors measured in women with and without PCOS. Across the cohort, higher concentrations of LPI(18:0) and lower concentrations of lipids containing docosahexaenoic acid (DHA, 22:6) n-3 polyunsaturated fatty acids were associated with higher adiposity, insulin resistance, fasting insulin, HbA1c and FAI, and lower SHBG.

CONCLUSION

Our data indicate that a distinct lipidomic signature comprising high LPI(18:0) and low DHA-containing lipids are associated with key metabolic risk factors that cluster in PCOS, independent of PCOS status. Prospective studies are needed to corroborate these findings in larger cohorts of women with varying PCOS phenotypes.

Abnormal Trabecular Bone Score, Lower Bone Mineral Density and Lean Mass in Young Women With Premature Ovarian Insufficiency Are Prevented by Oestrogen Replacement

BACKGROUND

Low bone density (BMD) and fractures commonly affect women with premature ovarian insufficiency (POI). However, bone microarchitecture and body composition data are lacking.

OBJECTIVE

To assess and characterise musculoskeletal phenotype and effects of oestrogen replacement therapy (ERT) in women with POI.

METHOD

Cross-sectional and longitudinal studies of 60 normal karyotype women with POI, aged 20-40 years, from 2005-2018. Dual x-ray absorptiometry (DXA)-derived spinal (LS) and femoral neck (FN) BMD, trabecular bone score (TBS), appendicular lean mass (ALM), total fat mass (TFM), and fracture prevalence were compared with 60 age-, and BMI-matched population-based controls. Longitudinal changes in bone and body composition variables and ERT effects were analysed using linear mixed models over a median duration of 6 years.

RESULTS

Women with POI were subdivided into spontaneous (s)-POI (n=25) and iatrogenic (i)-POI (n=35). Median(range) age of POI diagnosis was 34 (10-40) years with baseline DXA performed at median 1(0-13) year post-diagnosis. ERT was used by 82% women (similar for both POI groups). FN-BMD were lowest in s-POI (p<0.002). Low TBS was more common in s-POI [(44%), p=0.03], versus other groups. LS-BMD and ALM were lower in both s-POI and i-POI groups than controls (p<0.05). Fracture prevalence was not significantly different: 20% (s-POI), 17% (i-POI), and 8% (controls) (p=0.26). Longitudinal analysis of 23 POI women showed regular ERT was associated with ALM increment of 127.05 g/year (p<0.001) and protected against bone loss. However, ERT interruption was associated with annual reductions in FN BMD and TBS of 0.020g/cm² and 0.0070 (p<0.05), respectively.

CONCLUSION

Deficits in BMD, trabecular microarchitecture, and lean mass were present in women with POI. However, regular ERT protected against declines in bone variables, with an increase in ALM. Assessment of skeletal and muscle health, and advocating ERT adherence, is essential in POI to optimise musculoskeletal outcomes.

A Three-Year Longitudinal Study Comparing Bone Mass, Density, and Geometry Measured by DXA, pQCT, and Bone Turnover Markers in Children with PKU Taking L-Amino Acid or Glycomacropeptide Protein Substitutes

In patients with phenylketonuria (PKU), treated by diet therapy only, evidence suggests that areal bone mineral density (BMDa) is within the normal clinical reference range but is below the population norm. Aims: To study longitudinal bone density, mass, and geometry over 36 months in children with PKU taking either amino acid (L-AA) or casein glycomacropeptide substitutes (CGMP-AA) as their main protein source. Methodology: A total of 48 subjects completed the study, 19 subjects in the L-AA group (median age 11.1, range 5–16 years) and 29 subjects in the CGMP-AA group (median age 8.3, range 5–16 years). The CGMP-AA was further divided into two groups, CGMP100 (median age 9.2, range 5–16 years) (n = 13), children taking CGMP-AA only and CGMP50 (median age 7.3, range 5–15 years) (n = 16), children taking a combination of CGMP-AA and L-AA. Dual X-ray absorptiometry (DXA) was measured at enrolment and 36 months, peripheral quantitative computer tomography (pQCT) at 36 months only, and serum blood and urine bone turnover markers (BTM) and blood bone biochemistry at enrolment, 6, 12, and 36 months. Results: No statistically significant differences were found between the three groups for DXA outcome parameters, i.e., BMDa (L2–L4 BMDa g/cm²), bone mineral apparent density (L2–L4 BMAD g/cm³) and total body less head BMDa (TBLH g/cm²). All blood biochemistry markers were within the reference ranges, and BTM showed active bone turnover with a trend for BTM to decrease with increasing age. Conclusions: Bone density was clinically normal, although the median z scores were below the population mean. BTM showed active bone turnover and blood biochemistry was within the reference ranges. There appeared to be no advantage to bone density, mass, or geometry from taking a macropeptide-based protein substitute as compared with L-AAs.

Exercise and insulin resistance in PCOS: muscle insulin signalling and fibrosis

OBJECTIVE

Mechanisms of insulin resistance in polycystic ovary syndrome (PCOS) remain ill defined, contributing to sub-optimal therapies. Recognising skeletal muscle plays a key role in glucose homeostasis we investigated early insulin signalling, its association with aberrant transforming growth factor β (TGFβ)-regulated tissue fibrosis. We also explored the impact of aerobic exercise on these molecular pathways.

METHODS

A secondary analysis from a cross-sectional study was undertaken in women with (n = 30) or without (n = 29) PCOS across lean and overweight BMIs. A subset of participants with (n = 8) or without (n = 8) PCOS who were overweight completed 12 weeks of aerobic exercise training. Muscle was sampled before and 30 min into a euglycaemic-hyperinsulinaemic clamp pre and post training.

RESULTS

We found reduced signalling in PCOS of mechanistic target of rapamycin (mTOR). Exercise training augmented but did not completely rescue this signalling defect in women with PCOS. Genes in the TGFβ signalling network were upregulated in skeletal muscle in the overweight women with PCOS but were unresponsive to exercise training except for genes encoding LOX, collagen 1 and 3.

CONCLUSIONS

We provide new insights into defects in early insulin signalling, tissue fibrosis, and hyperandrogenism in PCOS-specific insulin resistance in lean and overweight women. PCOS-specific insulin signalling defects were isolated to mTOR, while gene expression implicated TGFβ ligand regulating a fibrosis in the PCOS-obesity synergy in insulin resistance and altered responses to exercise. Interestingly, there was little evidence for hyperandrogenism as a mechanism for insulin resistance.

Longitudinal changes in bone density in adolescents and young adults with cerebral palsy: A case for early intervention

CONTEXT

Cerebral palsy (CP) is a motor disorder affecting movement, muscle tone and posture due to damage to the foetal or infant brain. The subsequent lack of ambulation, nutritional deficiencies, anticonvulsant use and hormonal deficiencies have been implicated in the low bone mass associated with this condition.

OBJECTIVE

To assess changes in areal bone mineral density (aBMD) during adolescence and young adulthood in individuals with CP. The effect of ambulation, nutrition, hypogonadism on longitudinal changes in aBMD is also examined.

DESIGN

Retrospective longitudinal study.

SETTING AND PARTICIPANTS

Forty-five subjects with CP who had longitudinal dual-energy X-ray absorptiometry (DXA) scans at a single tertiary hospital between 2006 and 2018.

RESULTS

Mean age at first DXA was 19.4 years (range: 10-36 years), 57.8% were male and 80% were nonambulatory. The mean Z-scores at baseline were <-2.0 at all sites - lumbar spine (LS), femoral neck (FN), total hip (TH) and total body (TB). The median change in aBMD was +1.2%-1.9% per year in all subjects but in those <20 years of age, the median change was 4%-8% per year. Z-scores across all sites remained stable over time. Reduced functional state as measured by the gross motor functional classification scale (GMFCS) had a small negative effect on aBMD over time.

CONCLUSION

In adolescents with CP, low bone mass was evident from the baseline DXA. However, significant bone accrual occurred during the second decade, followed by bone maintenance in young adulthood. Future studies should focus on optimizing bone health from early childhood.

Measurement of Muscle Mass and Sarcopenia Using Anthropometry, Bioelectrical Impedance, and Computed Tomography in Surgical Patients with Colorectal Malignancy: Comparison of Agreement Between Methods

Background: Low skeletal muscle index (SMI) and sarcopenia adversely affect clinical outcomes in oncology patients. Study aims were to assess the agreement of bioelectrical impedance analysis (BIA), mid-arm muscle circumference (MAMC), and computed tomography (CT) at the third lumbar vertebra (L3), for the measurement of muscle mass and identification of sarcopenia, in patients with colorectal cancer (CRC).Method: A comparison study of low SMI and sarcopenia determined by BIA and MAMC, compared to CT. Sensitivity, specificity and area under the curve (AUC) were calculated.Results: CT scans were obtained for 100 participants. Low SMI was identified in 29%, 57%, and 20% of participants using CT at L3, BIA, and MAMC, respectively. For low muscle mass BIA showed 60% of participants were correctly classified (AUC 0.619, sensitivity 80%, specificity 52%, kappa 0.241, P = 0.009) and for MAMC, 73% of participants were correctly classified (AUC 0.625, sensitivity 38%, specificity 88%, kappa 0.286, P = 0.005). There were 14%, 31%, and 10% of participants identified as having sarcopenia from CT, BIA, and MAMC, respectively.Conclusions: Both BIA and MAMC show a poor level of agreement for measuring muscle mass compared to CT scans using L3 in patients with CRC.

A Cross-Sectional and Longitudinal Analysis of Trabecular Bone Score in Adults With Turner Syndrome

CONTEXT

Turner syndrome (TS) is associated with short stature, gonadal failure, and fractures. Spinal trabecular bone score (TBS) is a novel bone imaging modality that has not been evaluated in TS.

OBJECTIVE

To evaluate TBS in TS and its association with bone mineral density (BMD), prevalent fracture, and risk factors.

DESIGN AND SETTING

Longitudinal study of TS from a single tertiary hospital between 2006 and 2017.

PATIENTS OR OTHER PARTICIPANTS

Fifty-eight subjects with TS aged 20 to 49 years who underwent dual-energy X-ray absorptiometry (DXA).

MAIN OUTCOME MEASURES

TBS, DXA parameters, and prevalent fractures were investigated.

RESULTS

Normal, partially degraded, and degraded TBSs were observed in 39 (67%), 15 (26%), and four (7%) subjects, respectively. High rates of prescribed estrogen replacement therapy (ERT) with stable TBS and BMD were observed during follow-up. TBS was positively correlated with spine and femoral neck (FN) BMD and Z-scores (all P < 0.05) and negatively correlated with age (-0.004 per year; P = 0.014) and delay in ERT initiation in women with primary amenorrhea (-0.010 per year; P < 0.001). Fractures were present in 17 (31%) subjects. Low TBS had a significantly higher area under the receiver operator curve for predicting prevalent fracture than low bone mass at either the spine or FN (P < 0.05). Subjects with no history of fracture were more likely to have a normal TBS (P = 0.023).

CONCLUSIONS

BMD and TBS can be preserved with early initiation and continued use of ERT. TBS may provide additional fracture risk prediction to standard DXA parameters in TS and needs to be validated in larger prospective studies.

Fat-Bone Interactions in Adults With Spina Bifida

Context:

Spina bifida (SB) can lead to changes in body composition and bone mineral density (BMD) through diminished ambulation, renal impairment, and anticonvulsant medication. With increased life expectancy, diseases such as obesity and osteoporosis are emerging comorbidities in SB, with limited data to guide management.

Objective:

To examine the relationship between cardiometabolic factors, body composition, BMD, and minimal trauma fractures (MTFs) in adults with SB.

Design:

Retrospective cross-sectional study.

Setting and Participants:

Forty-nine adults with SB (median age, 32.7 years; interquartile range, 22.6 to 39.0) who had undergone dual-energy x-ray absorptiometry imaging at a single tertiary hospital from 2004 to 2015.

Results:

The mean body mass index was 31.7 ± 7.5 kg/m2; 26 (53.1%) were obese. Using age- and sex-matched fat percentiles from the National Health and Nutrition Examination Survey III, 62.5% had a total body percentage fat greater than the 95th percentile. Low bone mass (defined as a Z-score of ≤−2.0) was present in 21.9% at the L1 vertebra and in 35.1% at the femoral neck. Ten (20.4%) had a history of MTFs. A BMD or Z-score at L1, femoral neck, or total body site did not correlate with the occurrence of MTF. Fat mass was significantly and positively associated with BMD after adjustment for age, sex, and height and accounted for 18.6% of the variance in BMD (P = 0.005). The prevalence of metabolic comorbidities, such as hypertension (20.4%) and obstructive sleep apnea (16.3%), was high.

Conclusions:

Obesity and low BMD are common in young adults with SB. An increased fat mass correlated significantly with BMD. The prevalence of metabolic complications in patients with SB is increased and deserves further study.

Effects of testosterone treatment on body fat and lean mass in obese men on a hypocaloric diet: a randomised controlled trial

BACKGROUND

Whether testosterone treatment has benefits on body composition over and above caloric restriction in men is unknown. We hypothesised that testosterone treatment augments diet-induced loss of fat mass and prevents loss of muscle mass.

METHODS

We conducted a randomised double-blind, parallel, placebo controlled trial at a tertiary referral centre. A total of 100 obese men (body mass index ≥ 30 kg/m²) with a total testosterone level of or below 12 nmol/L and a median age of 53 years (interquartile range 47-60) receiving 10 weeks of a very low energy diet (VLED) followed by 46 weeks of weight maintenance were randomly assigned at baseline to 56 weeks of 10-weekly intramuscular testosterone undecanoate (n = 49, cases) or matching placebo (n = 51, controls). The main outcome measures were the between-group difference in fat and lean mass by dual-energy X-ray absorptiometry, and visceral fat area (computed tomography).

RESULTS

A total of 82 men completed the study. At study end, compared to controls, cases had greater reductions in fat mass, with a mean adjusted between-group difference (MAD) of -2.9 kg (-5.7 to -0.2; P = 0.04), and in visceral fat (MAD -2678 mm²; -5180 to -176; P = 0.04). Although both groups lost the same lean mass following VLED (cases -3.9 kg (-5.3 to -2.6); controls -4.8 kg (-6.2 to -3.5), P = 0.36), cases regained lean mass (3.3 kg (1.9 to 4.7), P < 0.001) during weight maintenance, in contrast to controls (0.8 kg (-0.7 to 2.3), P = 0.29) so that, at study end, cases had an attenuated reduction in lean mass compared to controls (MAD 3.4 kg (1.3 to 5.5), P = 0.002).

CONCLUSIONS

While dieting men receiving placebo lost both fat and lean mass, the weight loss with testosterone treatment was almost exclusively due to loss of body fat.

TRIAL REGISTRATION

clinicaltrials.gov, identifier NCT01616732 , registration date: June 8, 2012.

Low versus high dialysate calcium concentration in alternate night nocturnal hemodialysis: A randomized controlled trial

INTRODUCTION

Higher calcium dialysate is recommended for quotidian nocturnal hemodialysis (NHD) (≥6 nights/week) to maintain bone health. It is unclear what the optimal calcium dialysate concentration should be for alternate night NHD. We aimed to determine the effect of low calcium (LC) versus high calcium (HC) dialysate on cardiovascular and bone parameters in this population.

METHODS

A randomized controlled trial where participants were randomized to LC (1.3 mmol/L, n = 24) or HC dialysate (1.6 or 1.75 mmol/L, n = 26). Primary outcome was change in mineral metabolism markers. Secondary outcomes included change in vascular calcification (VC) scores [CT abdominal aorta (AA) and superficial femoral arteries (SFA)), pulse wave velocity (PWV), bone mineral density (BMD) and left ventricular mass index (LVMI) over 12 months.

FINDINGS

In the LC group, pre-dialysis ionised calcium decreased -0.12 mmol/L (-0.18-0.06, P = 0.0001) and PTH increased 16 pmol/L (3.5-28.5, p = 0.01) from baseline to 12 months with no significant change in the HC group. In both groups, there was no progression of VC in AA or SFA and no change in PWV, LVMI or BMD. At 12 months, calcimimetics were prescribed in a higher percentage in the LC vs. HC groups (45.5% vs. 10.5%) with a lower proportion of the HC group being prescribed calcitriol (31.5% vs. 72%).

DISCUSSION

Although dialysate calcium prescription influenced biochemical parameters it was not associated with difference in progression of VC between HC and LC groups. An important finding was the potential impact of alternate night NHD in attenuating progression of VC and inducing stabilisation of LVMI and PWV.

Musculoskeletal and Endocrine Health in Adults With Cerebral Palsy: New Opportunities for Intervention

CONTEXT

Cerebral palsy (CP) increases fracture risk through diminished ambulation, nutritional deficiencies, and anticonvulsant medication use. Studies examining bone mineral density (BMD) in adults with CP are limited.

OBJECTIVE

To examine the relationship between body composition, BMD, and fractures in adults with CP. The effect of functional, nutritional, and endocrine factors on BMD and body composition is also explored.

DESIGN

Retrospective cross-sectional study.

SETTING AND PARTICIPANTS

Forty-five adults with CP (mean age, 28.3 ± 11.0 years) who had dual-energy x-ray absorptiometry imaging at a single tertiary hospital between 2005 and 2015.

RESULTS

Seventeen (38%) had a past history of fragility fracture; 43% had a Z-score of ≤ -2.0 at the lumbar spine (LS) and 41% at the femoral neck (FN). In nonambulatory patients, every one unit decrease in FN Z-score increased the risk of fracture 3.2-fold (95% confidence interval, 1.07-9.70; P = .044). Stepwise linear regression revealed that the Gross Motor Function Classification System was the best predictor of LS Z-score (R(2) = 0.550; β = -0.582; P = .002) and FN Z-score (R(2) = 0.428; β = -0.494; P = .004); 35.7% of the variance in BMD was accounted for by lean tissue mass. Hypogonadism, present in 20% of patients, was associated with reduced lean tissue mass and reduced LS BMD. Lean tissue mass positively correlated with BMD in eugonadal patients, but not in hypogonadal patients.

CONCLUSIONS

Low BMD and fractures are common in adults with CP. This is the first study to document hypogonadism in adults with CP with detrimental changes in body composition and BMD.

Adherence to the gluten-free diet can achieve the therapeutic goals in almost all patients with coeliac disease: A 5-year longitudinal study from diagnosis

BACKGROUND

Key aims of treatment of coeliac disease are to heal the intestinal mucosa and correct nutritional abnormalities.

AIM

We aim to determine prospectively the degree of success and time course of achieving those goals with a gluten-free diet.

METHODS

Ninety-nine patients were enrolled at diagnosis and taught the diet. The first 52 were reassessed at 1 year and 46 at 5 years, 25 being assessed at the three time points regarding dietary compliance (dietitian-assessed), coeliac serology, bone mineral density and body composition analysis by dual energy X-ray absorptiometry, and intestinal histology.

RESULTS

Mean age (range) was 40 (18-71) years and 48 (76%) were female. Dietary compliance was very good to excellent in all but one. Tissue transglutaminase IgA was persistently elevated in 44% at 1 year and 30% at 5 years and were poorly predictive of mucosal disease. Rates of mucosal remission (Marsh 0) and response (Marsh 0/1) were 37% and 54%, and 50% and 85% at 1 and 5 years, respectively. Fat mass increased significantly over the first year in those with normal/reduced body mass index. Lean body mass indices more slowly improved irrespective of status at diagnosis with significant improvement at 5 years. Bone mass increased only in those with osteopenia or osteoporosis, mostly in year 1.

CONCLUSION

Dietary compliance is associated with a high chance of healing the intestinal lesion and correction of specific body compositional abnormalities. The time course differed with body fat improving within 1 year, and correction of the mucosal lesion and improvement in lean mass and bone mass taking longer.

Multi-component molecular-level body composition reference methods: evolving concepts and future directions

Excess adiposity is the main phenotypic feature that defines human obesity and that plays a pathophysiological role in most chronic diseases. Measuring the amount of fat mass present is thus a central aspect of studying obesity at the individual and population levels. Nevertheless, a consensus is lacking among investigators on a single accepted 'reference' approach for quantifying fat mass in vivo. While the research community generally relies on the multi-component body volume class of 'reference' models for quantifying fat mass, no definable guide discerns among different applied equations for partitioning the four (fat, water, protein and mineral mass) or more quantified components, standardizes 'adjustment' or measurement system approaches for model-required labelled water dilution volumes and bone mineral mass estimates, or firmly establishes the body temperature at which model physical properties are assumed. The resulting differing reference strategies for quantifying body composition in vivo leads to small, but under some circumstances, important differences in the amount of measured body fat. Recent technological advances highlight opportunities to expand model applications to new subject groups and measured components such as total body protein. The current report reviews the historical evolution of multi-component body volume-based methods in the context of prevailing uncertainties and future potential.

Polycystic ovary syndrome and anti-Müllerian hormone: role of insulin resistance, androgens, obesity and gonadotrophins

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder associated with insulin resistance, hyperandrogenism, obesity, altered gonadotrophin release and anovulatory infertility. Anti-Müllerian hormone (AMH) has been proposed as a marker of ovarian function and fertility. Across a cohort of lean and overweight women with and without PCOS, we investigated the association of AMH with insulin resistance and body composition using gold standard measures. A secondary aim was to examine whether AMH was useful to determine PCOS status.

DESIGN

Cross-sectional study.

PATIENTS

A total of 22 lean and 21 overweight women with PCOS and 19 lean and 16 overweight non-PCOS healthy controls were recruited. PCOS was diagnosed based on the Rotterdam criteria.

MEASUREMENTS

Euglycaemic-hyperinsulinaemic clamp for assessing insulin resistance, dual energy X-ray absorptiometry and computed tomography for assessing adiposity, and blood sampling for the assessment of androgens, gonadotrophins and AMH.

RESULTS

Anti-Müllerian hormone levels were increased in women with PCOS (P <0·001) regardless of adiposity, with this increase associated with testosterone (P <0·001) rather than insulin resistance (P = 0·79), adiposity (P = 0·98) or gonadotrophins. In assessing the ability of AMH to predict PCOS, a value of 30 pmol/l or higher indicated 79% of women with PCOS were correctly identified as having the condition.

CONCLUSION

Anti-Müllerian hormone appears primarily related to androgen status suggesting a direct and predominant role of androgens in the pathophysiology of reproductive dysfunction in PCOS. As AMH reflects PCOS status, it may also be useful in PCOS diagnosis.

Thalassemia bone disease: a 19-year longitudinal analysis

Thalassemia is an inherited disorder of alpha or beta globin chain synthesis leading to ineffective erythropoiesis requiring chronic transfusion therapy in its most severe form. This leads to iron overload, marrow expansion, and hormonal complications, which are implicated in bone deformity and loss of bone mineral density (BMD). In this 19-year retrospective longitudinal study, the relationships between BMD (determined by dual-energy X-ray absorptiometry) and risk factors for osteoporosis in 277 subjects with transfusion-dependent thalassemia were examined. The mean age at first review was 23.2 ± 11.9 years and 43.7% were male. Hypogonadism was present in 28.9%. Fractures were confirmed in 11.6% of subjects and were more frequent in males (16.5%) compared with females (7.7%). Lumbar spine (LS), femoral neck (FN), and total body (TB) Z-scores were derived. Patients with transfusion-dependent thalassemia had a significant longitudinal decline in BMD at the FN and TB. In the linear mixed-model analysis of BMD and risk factors for bone loss, FN Z-score was more significantly associated with risk factors compared with the LS and TB. The rate of decline at the FN was 0.02 Z-score per year and was 3.85-fold greater in males. The decline in FN Z-score over the last 5 years (years 15 to 19) was 2.5-fold that of the previous 7 years (years 8 to 14) and coincided with a change in iron chelator therapy from desferrioxamine to deferasirox. Hemoglobin (Hb) levels positively correlated with higher TB and LS Z-scores. In conclusion, the FN is the preferred site for follow-up of BMD. Male patients with β-thalassemia experienced a greater loss of BMD and had a higher prevalence of fractures compared with females. Transfusing patients (particularly males) to a higher Hb target may reduce the decline in BMD. Whether deferasirox is implicated in bone loss warrants further study.

Relationship between mental health and foot pain

OBJECTIVE

Although mental health is related to the persistence of musculoskeletal pain, our understanding of the relationship between mental health and foot pain is limited. Subsequently, we conducted a 3-year longitudinal study to examine the relationship between mental health and foot pain in a community-based population.

METHODS

Eighty-three community-dwelling participants (mean ± SD body mass index [BMI] 35.3 ± 9.0 kg/m2) who had foot pain at study inception in 2008 and for whom measures of mental health (Short Form 36 [SF-36] health survey mental component summary [MCS]) were available, were invited to take part in this followup study in 2011. Change in foot pain was determined by the difference between the Manchester Foot Pain and Disability Index score at baseline and followup; therefore, a decrease in the score indicated improved foot pain and an increase indicated deterioration in foot pain. Linear regression was used to determine the factors affecting change in foot pain.

RESULTS

Of the 62 respondents (75% response rate, 49 women and 13 men), there were 27 (44%) whose foot pain deteriorated. A higher MCS score of the SF-36 health survey at baseline was associated with a slower progression of foot pain (β coefficient −0.29, 95% confidence interval −0.42, −0.01), adjusted for age, sex, BMI, and physical health.

CONCLUSION

Mental health is associated with changes in foot pain. Clinicians dealing with this population should consider the contribution of mental health in their management and treatment of foot pain.

Effect of testosterone treatment on glucose metabolism in men with type 2 diabetes: a randomized controlled trial

OBJECTIVE

To determine whether testosterone therapy improves glucose metabolism in men with type 2 diabetes (T2D) and lowered testosterone.

RESEARCH DESIGN AND METHODS

We conducted a randomized, double-blind, parallel, placebo-controlled trial in 88 men with T2D, aged 35-70 years with an HbA1c ≤8.5% (69 mmol/mol), and a total testosterone level, measured by immunoassay, of ≤12.0 nmol/L (346 ng/dL). Participants were randomly assigned to 40 weeks of intramuscular testosterone undecanoate (n = 45) or matching placebo (n = 43). All study subjects were included in the primary analysis. Seven men assigned to testosterone and six men receiving placebo did not complete the study. Main outcome measures were insulin resistance by homeostatic model assessment (HOMA-IR, primary outcome) and glycemic control by HbA1c (secondary outcome).

RESULTS

Testosterone therapy did not improve insulin resistance (mean adjusted difference [MAD] for HOMA-IR compared with placebo -0.08 [95% CI -0.31 to 0.47; P = 0.23]) or glycemic control (MAD HbA1c 0.36% [0.0-0.7]; P = 0.05), despite a decrease in fat mass (MAD -2.38 kg [-3.10 to -1.66]; P < 0.001) and an increase in lean mass (MAD 2.08 kg [1.52-2.64]; P < 0.001). Testosterone therapy reduced subcutaneous (MAD -320 cm(3) [-477 to -163]; P < 0.001) but not visceral abdominal adipose tissue (MAD 140 cm(3) [-89 to 369]; P = 0.90).

CONCLUSIONS

Testosterone therapy does not improve glucose metabolism or visceral adiposity in obese men with moderately controlled T2D and modest reductions in circulating testosterone levels typical for men with T2D.

Weight change and change in tibial cartilage volume and symptoms in obese adults

INTRODUCTION

There is a paucity of data examining the effects of weight change on knee joint structures and symptoms. This study examined the effect of weight change on change in knee cartilage volume and symptoms in an obese cohort.

METHODS

112 obese subjects (Body Mass Index ≥30 kg/m(2)) were recruited from various community sources to examine the effect of obesity on musculoskeletal health. Tibial cartilage volume, determined by MRI, and knee symptoms, determined by the Western Ontario and McMaster Osteoarthritis Index (WOMAC) were collected at baseline and an average of 2.3 years later.

RESULTS

Percentage weight change was associated with change in medial tibial cartilage volume (β -1.2 mm(3), 95% CI -2.3 to -0.1 mm(3), p=0.03) that was consistent throughout the spectrum of weight loss through to mild weight gain. Percentage weight change was not associated with change in the lateral tibial (p=0.93) or patella (p=0.32) cartilage volumes. Percentage weight change was associated with change in all WOMAC subscales (all p≤0.01): pain (β -1.8 mm, 95% CI -3.2 to -0.4 mm), stiffness (β -1.6 mm, 95% CI -2.5 to -0.7 mm) and function (β -6.9 mm, 95% CI -11.6 to -2.1 mm).

CONCLUSIONS

The linearity of effect implies that weight loss is associated with reduced medial cartilage volume loss and improved knee symptoms, while weight gain is associated with increased medial cartilage volume loss and worse knee symptoms. These results suggest that in obese people, small amounts of weight change may have the potential for a disease modifying effect on both knee joint structure and symptoms. While weight loss is an important primary management strategy in obese individuals, avoidance of further weight gain should also be a clinical goal.

The effect of gonadal status on body composition and bone mineral density in transfusion-dependent thalassemia

Patients with transfusion-dependent thalassemia have abnormal growth, hormonal deficits, and increased bone loss. We investigated the relationship between skeletal muscle mass, fat mass, and bone mineral density in adult subjects with transfusion-dependent thalassemia based on their gonadal status. Our findings show that hypogonadism attenuates the strength of the muscle-bone relationship in males but strengthens the positive correlation of skeletal muscle mass and fat mass in female subjects.

INTRODUCTION

Transfusion-dependent thalassemia is associated with a high prevalence of fractures. Multiple hormonal complications, in particular hypogonadism, can lead to changes in body composition and bone mineral density (BMD). We investigated for the first time the relationship between skeletal muscle mass (SMM), fat mass, and BMD in adult subjects with transfusion-dependent thalassemia based on their gonadal status.

METHODS

A retrospective cohort study of 186 adults with transfusion-dependent thalassemia was analyzed. Body composition and BMD were measured using dual energy X-ray absorptiometry. The association between skeletal muscle, fat, and BMD was investigated through uni-, multi-, and stepwise regression analyses after adjusting for multicollinearity. SMM was derived using the formula, SMM = 1.19 × ALST-1.65, where ALST is equivalent to the sum of both arm and leg lean tissue mass.

RESULTS

There were 186 subjects, males (43.5 %) and females (56.5 %), with a median age of 36.5. Hypogonadism was reported in 44.4 % of males and 44.7 % of females. SMM and BMD were positively correlated and strongest in eugonadal males (0.36 ≤ R (2) ≤ 0.59), but the association was attenuated in hypogonadal males. SMM (0.27 ≤ R (2) ≤ 0.69) and total fat mass (0.26 ≤ R (2) ≤ 0.55) were positively correlated with BMD in hypogonadal females, but the correlation was less pronounced in eugonadal females. Leg lean tissue mass and arm lean tissue mass in males and females, respectively, were most highly correlated to BMD in the stepwise regression analysis.

CONCLUSION

Hypogonadism attenuates the strength of the muscle-bone relationship in males but strengthens the positive correlation of skeletal muscle mass and fat mass in female subjects. This study supports the notion that exercise is important for maintaining BMD and the need to optimize treatment of hypogonadism in patients with transfusion-dependent thalassemia.

Fat mass is a predictor of incident foot pain

OBJECTIVE

Foot pain is a common complaint in adults. Increased BMI and fat mass have been linked only to foot pain prevalence. Therefore, a longitudinal study to examine the relationship between body composition and incident foot pain over 3 years was conducted.

DESIGN AND METHODS

Sixty-one community dwelling participants from a previous study of musculoskeletal health, who did not have foot pain at study inception in 2008, were invited to take part in this follow-up study in 2011. Current foot pain was determined using the Manchester Foot Pain and Disability Index, and body composition was measured using dual X-ray absorptiometry at study baseline.

RESULTS

Of the 51 respondents (84% response rate, 37 females and 14 males), there were 11 who developed foot pain. BMI ranged from underweight to morbidly obese (17-44 kg/m2), mean 27.0 ± 6.0 kg/m2. Incident foot pain was positively associated with both fat mass (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.03-1.20) and fat-mass index (OR 1.28, 95% CI 1.04-1.57) in multivariate analysis.

CONCLUSIONS

Fat mass is a predictor of incident foot pain. This study supports the notion that incident foot pain in overweight individuals is associated with fat mass rather than body mass alone.

Thalassemia bone disease: the association between nephrolithiasis, bone mineral density and fractures

Thalassemia bone disease is well described, but the prevalence of nephrolithiasis has not been characterized. The association between nephrolithiasis, reduced bone density, and increased fractures has been demonstrated through this retrospective study of 166 participants with transfusion-dependent thalassemia. The findings support the need for increased vigilance of kidney and bone disease in this cohort.

INTRODUCTION

Previous studies have revealed that thalassemia is associated with reduced bone mineral density (BMD) and fractures. Many causes are implicated including hypogonadism, growth hormone deficiency, marrow expansion, and iron overload. Nephrolithiasis is associated with reduced BMD and increased fractures in the general population. However, the prevalence of nephrolithiasis and its association with bone density and fractures have not been characterized in thalassemia.

METHODS

We have addressed this question by performing a retrospective cohort study of 166 participants with transfusion-dependent thalassemia who had undergone dual-energy X-ray absorptiometry between 2009 and 2011. Logistic regression modeling was used to adjust for potential confounders.

RESULTS

We found a high prevalence of kidney stones (18.1 %) which was greater in males compared to females (28.7 vs 9.7 %, respectively). Renal stones were associated with reduced femoral neck Z-score and fractures in men after adjusting for potential confounders. These results indicate that nephrolithiasis is highly prevalent in patients with transfusion-dependent thalassemia and is significantly associated with reduced BMD and increased fractures.

CONCLUSIONS

The findings from this study strongly support the need for ongoing surveillance of BMD, fractures, and nephrolithiasis in the management of transfusion-dependent thalassemia.

Skeletal muscle mass in hospitalized elderly patients: comparison of measurements by single-frequency BIA and DXA

BACKGROUND & AIMS

There is increasing interest in estimating skeletal muscle mass (SMM) in clinical practice. We aimed to validate a bioelectrical impedance analysis (BIA) prediction equation for SMM, developed in a different healthy elderly population, in a population of hospital patients aged 70 and over, by comparison with dual-energy X-ray absorptiometry (DXA) SMM estimates. Comparison was also made with two other previously published BIA muscle prediction equations.

METHODS

Muscle measurements by BIA and DXA were compared in 117 patients with a range of clinical conditions (45 female, 72 male, mean age 75 years).

RESULTS

The BIA equation used yielded an accurate estimate of DXA-derived SMM. Mean (SD) difference was 0.26(1.79) kg (ns). The two other BIA equations over-estimated SMM compared to DXA (both p < 0.001), but all equations were highly correlated.

CONCLUSIONS

The BIA equation used, developed in a different healthy elderly population, gave an accurate estimate of DXA-derived SMM in a population with various clinical disorders. BIA appears potentially capable to estimate SMM in clinical disorders, but the optimal approach to its use for this purpose requires further investigation.

Optimizing healthy gestational weight gain in women at high risk of gestational diabetes: a randomized controlled trial

OBJECTIVE

Optimizing gestational weight gain (GWG) in early pregnancy is of clinical and public health importance, especially in higher risk pregnancies.

DESIGN AND METHODS

In a robustly designed, randomized controlled trial, 228 pregnant women at risk of developing gestational diabetes mellitus (GDM) were allocated to either control (written health information only) or intervention (four-session lifestyle program). All women received standard maternal care. Measures were completed at 12-15 and 26-28 weeks gestation. Measures included anthropometrics (weight and height), physical activity (pedometer and International Physical Activity Questionnaire), questionnaires (risk perception), and GDM screening.

RESULTS

The mean (SD) age [31.7 (4.5) and 32.4 (4.7) years] and body mass index [BMI; 30.3 (5.9) and 30.4 (5.6) kg/m(2) ] were similar between control and intervention groups, respectively. By 28 weeks, GWG was significantly different between control and intervention groups [6.9 (3.3) vs. 6.0 (2.8) kg, P < 0.05]. When stratified according to baseline BMI, overweight women in the control group gained significantly more weight compared to overweight women in the intervention group [7.8 (3.4) vs. 6.0 (2.2) kg, P < 0.05], yet in obese women, GWG was similar in both groups. Physical activity levels declined by 28 weeks gestation overall (P < 0.01); however, the intervention group retained a 20% higher step count compared to controls [5,203 (3,368) vs. 4,140 (2,420) steps/day, P < 0.05]. Overall, GDM prevalence was 22.8% [Corrected], with a trend toward less cases in the intervention group (P = 0.1).

CONCLUSIONS

Results indicate that a low-intensity lifestyle intervention, integrated with antenatal care, optimizes healthy GWG and attenuates physical activity decline in early pregnancy. Efficacy in limiting weight gain was greatest in overweight women and in high-risk ethnically diverse women.

Improved 4-compartment body-composition model for a clinically accessible measure of total body protein

BACKGROUND

Muscle wasting is a consequence of many primary conditions including sarcopenia, cachexia, osteoporosis, HIV/AIDS, and chronic kidney disease. Unfortunately, there is not a clinically accessible method to measure total body protein, which is the functional mass of muscle.

OBJECTIVE

We sought to derive a simple method to measure total body protein by using dual-energy X-ray absorptiometry (DXA) and bioimpedance analysis (BIA).

DESIGN

We retrospectively analyzed a clinical convenience sample of individuals with numerous metabolic conditions from the Monash Medical Centre, Melbourne, Australia, who had a concurrent protein measure by using neutron activation analysis-derived protein (NAA-TBPro), water measure by using BIA, and whole-body DXA scan. The study was split into calibration and validation data sets by using simple random sampling stratified by sex, BMI category, and age decade. We generated a protein estimate direct-calibration protein (DC-TBPro) derived from BIA water, bone mass, and body volume. We compared NAA-TBPro with DC-TBPro and 2 protein estimates from the literature, one that used the DC-TBPro equation with fixed coefficients [4-compartment Lohman method for analysis of total body protein (4CL-TBPro)] and another that used fat-free mass, age, and sex [Wang equation-derived protein (W-TBPro)].

RESULTS

A total of 187 participants [119 women; mean (±SD) age: 37.0 ± 15.4 y; mean (±SD) BMI (in kg/m(2)) 24.5 ± 7.7] were included. When plotted against NAA-TBPro, DC-TBPro had the highest correlation [coefficient of determination (R(2)) = 0.87], lowest root mean squared error (RMSE; 0.87 kg), and fewest outliers compared with 4CL-TBPro (R(2) = 0.75; RMSE = 1.22 kg) and W-TBPro (R(2) = 0.80; RMSE = 1.10 kg).

CONCLUSIONS

A simple method to measure total body protein by using a DXA system and BIA unit was developed and compared with NAA as proof of principle. With additional validation, this method could provide a clinically useful way to monitor muscle-wasting conditions.

Pigment epithelium-derived factor, insulin sensitivity, and adiposity in polycystic ovary syndrome: impact of exercise training

Pigment epithelium-derived factor (PEDF) is upregulated in obese rodents and is involved in the development of insulin resistance (IR). We aim to explore the relationships between PEDF, adiposity, insulin sensitivity, and cardiovascular risk factors in obese women with polycystic ovary syndrome (PCOS) and weight-matched controls and to examine the impact of endurance exercise training on PEDF. This prospective cohort intervention study was based at a tertiary medical center. Twenty obese PCOS women and 14 non-PCOS weight-matched women were studied at baseline. PEDF, cardiometabolic markers, detailed body composition, and euglycemic-hyperinsulinemic clamps were performed and measures were repeated in 10 PCOS and 8 non-PCOS women following 12 weeks of intensified aerobic exercise. Mean glucose infusion rate (GIR) was 31.7% lower (P = 0.02) in PCOS compared to controls (175.6 ± 96.3 and 257.2 ± 64.3 mg.m(-2).min(-1)) at baseline, yet both PEDF and BMI were similar between groups. PEDF negatively correlated to GIR (r = -0.41, P = 0.03) and high-density lipoprotein (HDL) (r = -0.46, P = 0.01), and positively to cardiovascular risk factors, systolic (r = 0.41, P = 0.02) and diastolic blood pressure (r = 0.47, P = 0.01) and triglycerides (r = 0.49, P = 0.004). The correlation with GIR was not significant after adjusting for fat mass (P = 0.07). Exercise training maintained BMI and increased GIR in both groups; however, plasma PEDF was unchanged. In summary, PEDF is not elevated in PCOS, is not associated with IR when adjusted for fat mass, and is not reduced by endurance exercise training despite improved insulin sensitivity. PEDF was associated with cardiovascular risk factors, suggesting PEDF may be a marker of cardiovascular risk status.

Less fat reduction per unit weight loss in type 2 diabetic compared with nondiabetic obese individuals completing a very-low-calorie diet program

The objective was to compare weight loss and change in body composition in obese subjects with and without type 2 diabetes mellitus during a very-low-calorie diet (VLCD) program. Seventy weight-matched subjects with diabetes or normal fasting glucose (controls) participated in a 24-week VLCD study. Primary end points were changes in anthropometry, body composition, and fasting plasma insulin and β-hydroxybutyrate concentrations. Fifty-one subjects (24 with diabetes) completed the study. No difference in weight loss between the 2 groups at 24 weeks was found by intention-to-treat analysis. Both groups completing the study per protocol had near-identical weight change during the program, with similar weight loss at 24 weeks (diabetes: 8.5 ± 1.3 kg vs control: 9.4 ± 1.2 kg, P = .64). Change in fat mass index correlated with change in body mass index (BMI) in both groups (diabetes: r = 0.878, control: r = 0.920, both P < .001); but change in fat mass index per unit change in BMI was less in the diabetic group compared with controls (0.574 vs 0.905 decrease, P = .003), which persisted after adjusting for age, sex, and baseline BMI (P = .008). Insulin concentrations remained higher and peak β-hydroxybutyrate concentrations were lower in the diabetic compared with the control group. While following a 24-week VLCD program, obese subjects with and without diabetes achieved comparable weight loss; but the decrease in adiposity per unit weight loss was attenuated in diabetic subjects. Hyperinsulinemia may have inhibited lipolysis in the diabetic group; however, further investigation into other factors is needed.

Effect of exercise training on insulin sensitivity, mitochondria and computed tomography muscle attenuation in overweight women with and without polycystic ovary syndrome

AIMS/HYPOTHESIS

Polycystic ovary syndrome (PCOS) is an insulin resistant (IR) state. Increased skeletal muscle lipid content and impaired mitochondrial biogenesis have been implicated in the pathogenesis of IR. We investigated whether differences in these variables explain the IR of women affected by PCOS and whether improvements in IR with exercise are reflected by changes in these variables.

METHODS

Sixteen PCOS and 13 non-PCOS overweight women were assessed, and eight PCOS and seven non-PCOS women were reassessed after 12 weeks of moderate and vigorous exercise training. Outcomes included insulin sensitivity (glucose infusion rate [GIR]), skeletal muscle gene expression and protein abundance, enzyme activity of selected mitochondrial components, and computed tomography (CT) attenuation-estimated muscle lipid.

RESULTS

GIR was lower in women with PCOS versus those without (p = 0.01) and increased with exercise in both groups. Baseline CT muscle attenuation suggested a trend to less muscle lipid in PCOS, which increased with exercise training, with a difference in the change in muscle lipid (p = 0.01, age-corrected), compared with non-PCOS women. GIR correlated with PGC1A gene expression across the whole group; skeletal muscle expression of mitochondrial biogenesis markers was not different between groups at baseline, or after training. Neither lipid changes nor mitochondrial changes correlated with changes in GIR.

CONCLUSIONS/INTERPRETATION

Differences in IR in women with and without PCOS were not explained by differences in skeletal muscle lipid or mitochondrial parameters. Improvements in IR with exercise were dissociated from mitochondrial parameters. CT muscle attenuation suggested a differential capacity of PCOS muscle to store lipid compared with non-PCOS.

TRIAL REGISTRATION

Clinicaltrials.gov ISRCTN84763265.

FUNDING

National Health & Medical Research Council (Grant number 606553), Monash University and The Jean Hailes Foundation.

A case of hypophosphatemic osteomalacia secondary to deferasirox therapy

Patients with β-thalassemia major require iron-chelation therapy to avoid the complication of iron overload. Until recently, deferoxamine (DFO) was the major iron chelator used in patients requiring chronic hypertransfusion therapy, but DFO required continuous subcutaneous therapy. The availability of deferasirox (Exjade®), an orally active iron chelator, over the past 4 years represented a necessary alternative for patients requiring chelation therapy. However, there have been increasing reports of proximal renal tubular dysfunction and Fanconi syndrome associated with deferasirox in the literature. We report a case of hypophosphataemic osteomalacia secondary to deferasirox therapy.

Exercise decreases anti-müllerian hormone in anovulatory overweight women with polycystic ovary syndrome: a pilot study

Polycystic ovary syndrome (PCOS) is a common condition in women associated with menstrual irregularity and anovulation. While obesity worsens and weight loss or exercise improves reproduction function in PCOS, the mechanism for this is unclear. The aim of this study was to examine the effect of exercise on ovarian hormones [anti-Müllerian hormone (AMH)] and menstrual and ovulatory function in women with and without PCOS. Overweight women with (n=7) and without (n=8) PCOS of comparable age, weight and BMI undertook a 12-week intensified endurance exercise training program (1 h 3 times/week) with no structured energy restriction. Primary outcomes were AMH, ovulation (weekly urinary pregnanediol) and menstrual regularity. Secondary outcomes were insulin resistance (euglycemic hyperinsulinemic clamp) and body composition (computed tomography and dual X-ray absorptiometry). Exercise decreased BMI, total and android fat mass and improved insulin sensitivity for all women. AMH was significantly higher in women with PCOS compared to controls before (p<0.001) and after exercise (p=0.001). There was a significant interaction between AMH changes with exercise and PCOS status (p=0.007) such that women without PCOS had no change in AMH (+1.4±5.2 pmol/l, p=0.48) while women with PCOS had a decrease in AMH (- 13.2±11.7 pmol/l, p=0.025). Exercise is associated with improvements in ovarian hormones in women with abnormal ovarian function. This suggests that mechanisms associated with ovarian dysfunction can be improved by exercise in PCOS.

Longitudinal body composition changes due to dialysis

BACKGROUND AND OBJECTIVES

Nutritional status remains a powerful predictor of outcome in the dialysis population. High body mass index (BMI) seems protective, but which body compartment (fat or lean mass) confers this protection remains unclear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a longitudinal study (n = 60; n = 46 completed) examining changes in body composition in incident peritoneal dialysis (PD) and hemodialysis (HD) patients over 12 months. We measured total body protein (TBP) by in vivo neutron activation, expressed as nitrogen index (NI), and lean body mass (LBM) and total body fat (TBF) by dual-energy x-ray absorptiometry. Visceral and subcutaneous fat areas (SFAs) were determined from computed tomography. Comparisons were made between different BMI groups and dialysis modalities.

RESULTS

No significant change was found in TBP, NI, or TBF. The obese group (BMI >30) had an increase in all mean LBM parameters with a significant increase in NI compared with normal-weight and the overweight group. This increase in NI remained significant after multivariate analysis β coefficient (0.08). PD patients had the greatest increase in TBF, with a significant increase in visceral fat (VFA:SFA ratio β coefficient = 0.23).

CONCLUSIONS

Obese patients showed preservation of TBP compared with normal- and overweight patients, suggesting that energy storage as fat mass is of value in the dialysis population.

Bone mineral content and density in Rett syndrome and their contributing factors

This study used densitometry to investigate the areal bone mineral density (aBMD) and bone mineral content (BMC) in an Australian Rett syndrome cohort and to assess how factors such as genotype, epilepsy, BMI, and mobility affect these parameters. The influence of lean tissue mass (LTM) and bone area (BA) on total body BMC (TBBMC) was also investigated. Participants, recruited from the Australian Rett Syndrome Database (ARSD), had TBBMC and lumbar spine (LS) and femoral neck (FN) aBMD measured using Dual energy x-ray absorptiometry. Mean height standardized Z scores and CIs for the bone outcomes were obtained from multiple regression models. The mean height Z score for the FN aBMD was low at -2.20, while the LS aBMD was -0.72. The TBBMC mean height Z score was -0.62, although once adjusted for BA and LTM, the mean was above zero, suggesting that low BMC can be explained by narrow bones and decreased muscle mass, likely secondary to decreased mobility. Multiple linear regression identified the p.R168× and p.T158M mutations as the strongest predictors of low aBMC and BMD for all bone outcomes. The strong relationship between genotype, BMC, and aBMD is likely underpinned by the strong relationship between LTM, mobility, and bone outcome measures.

Poor physical function in elderly women in low-level aged care is related to muscle strength rather than to measures of sarcopenia

Purpose:

To determine the prevalence of sarcopenia and investigate relationships among body composition, muscle strength, and physical function in elderly women in low-level aged care.

Subjects and methods:

Sixty-three ambulatory women (mean age 86 years) participated in this cross-sectional study where body composition was determined by dual energy X-ray absorptiometry (DXA); ankle, knee, and hip strength by the Nicholas Manual Muscle Tester; and physical function by ‘timed up and go’ (TUG) and walking speed (WS) over 6 meters. Body composition data from a female reference group (n = 62, mean age 29 years) provided cut-off values for defining sarcopenia.

Results:

Elderly women had higher body mass index (P < 0.001), lower lean mass (P < 0.001), and higher fat mass (P < 0.01) than the young reference group. Only a small proportion (3.2%) had absolute sarcopenia (defined by appendicular skeletal muscle mass/height squared) whereas 37% had relative sarcopenia class II (defined by percentage skeletal muscle mass). Scores for TUG and WS indicated relatively poor physical function, yet these measures were not associated with muscle mass or indices of sarcopenia. In multivariate analysis, only hip abductor strength predicted both TUG and WS (both P = 0.01).

Conclusion:

Hip strength is a more important indicator of physical functioning than lean mass. Measurement of hip strength may therefore be a useful screening tool to detect those at risk of functional decline and requirement for additional care. Further longitudinal studies with a range of other strength measures are warranted.

Increase in visceral and subcutaneous abdominal fat in men with prostate cancer treated with androgen deprivation therapy

OBJECTIVE

Androgen deprivation therapy (ADT) for prostate cancer is associated with increases in fat mass and risk of type 2 diabetes; however, the relationship between sex steroid deficiency and abdominal fat distribution remains controversial.

DESIGN

We conducted a 12-month prospective observational study at a tertiary referral centre.

PATIENTS AND MEASUREMENTS

We investigated changes in abdominal fat distribution and insulin resistance in 26 men (70.6±6.8 years) with nonmetastatic prostate cancer during the first year of ADT.

RESULTS

Twelve months of ADT increased visceral abdominal fat area by 22% (from 160.8±61.7 to 195.9±69.7 cm(2) ; P<0.01) and subcutaneous abdominal fat area by 13% (from 240.7±107.5 to 271.3±92.8 cm(2) ; P<0.01). Fat mass increased by 14% (+3.4 kg; P<0.001) and lean tissue mass decreased by 3.6% (-1·9 kg; P<0.001). Insulin resistance (HOMA-IR) increased by 12% (2.50±1.12 to 2.79±1.31, P<0.05). There was no change in fasting glucose or glycated haemoglobin levels. Total testosterone (TT) was inversely associated with visceral fat area independent of oestradiol (E2), but E2 was not associated with visceral fat area independent of TT. Visceral fat area, not TT or E2, was independently associated with insulin resistance.

CONCLUSIONS

ADT for prostate cancer results in accumulation of both visceral and subcutaneous abdominal fat. Increased visceral fat area appears more closely linked to testosterone than oestradiol deficiency. Increased insulin resistance may arise secondary to visceral fat accumulation, rather than as a direct result of sex steroid deficiency.

Effects of exercise on insulin resistance and body composition in overweight and obese women with and without polycystic ovary syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is an insulin-resistant (IR) state. Visceral fat (VF) is independently associated with IR.

OBJECTIVES

The objectives of the study were to explore mechanisms underpinning IR by assessing the effect of exercise training on IR and body composition in overweight PCOS and non-PCOS women.

DESIGN

This was a prospective exercise intervention study.

SETTING AND PARTICIPANTS

The study was conducted at an academic medical center. Participants included 20 overweight PCOS and 14 overweight non-PCOS women.

INTERVENTION

The intervention included 12 wk of intensified aerobic exercise (3 h/wk).

MAIN OUTCOME MEASURES

IR on euglycemic hyperinsulinemic clamp, body composition including abdominal visceral and sc fat distribution by computer tomography and lipids was measured.

RESULTS

PCOS subjects were more IR (P = 0.02) and had more VF (P = 0.04 age adjusted) than non-PCOS women. In PCOS women, IR correlated with VF (r = -0.78, P < 0.01). With exercise training, both groups maintained weight but within PCOS, VF (-12.0 cm(2), P = 0.03) and within non-PCOS abdominal sc fat (-40.2 cm(2), P = 0.02) decreased. Despite exercise-induced improvement in IR within PCOS (+27.9 mg · m(-2) · min(-1), P = 0.03), no relationship with decreased VF (r = -0.08, P = 0.84) and no differential changes in IR and VF between groups were noted. Triglycerides decreased within PCOS (-0.27 mmol/liter, P = 0.02) and decreased differentially between groups (P < 0.01).

CONCLUSIONS

Higher IR was related to increased VF in PCOS, suggesting an etiological role for VF in intrinsic IR in PCOS; however, changes with exercise intervention did not support a causal relationship. Triglycerides were modulated more by exercise training in PCOS than non-PCOS women. Within-group exercise-induced reductions in cardiometabolic risk factors including IR, triglycerides, and VF in PCOS were observed without significant weight loss and if confirmed in future controlled trials, suggest weight loss should not be the sole focus of exercise programs.

Using vertebral bone densitometry to determine aortic calcification in patients with chronic kidney disease

BACKGROUND

Vascular calcification (VC) is a major contributor to increased cardiovascular (CV) disease in chronic kidney disease (CKD) and an independent predictor of mortality. VC is inversely correlated with bone mineral density (BMD). Screening for VC may be useful to determine those at greater CV risk and dual-energy X-ray absorptiometry (DXA) may have a dual role in providing VC measurement as well as BMD.

METHODS

We report cross-sectional data on 44 patients with CKD stages 3-4 and aim to determine and validate measurement of VC using DXA. Patients had computed tomography (CT) of abdominal aorta and DXA of lateral lumbar spine, to determine both aortic VC and BMD. Semi-quantitative measurement of VC from DXA was determined (blinded) using previously validated 8- and 24-point scales, and compared with VC from CT. BMD determination from L2 to L4 vertebrae on CT was compared with DXA-reported BMD.

RESULTS

Patients 66% male, 57% diabetic, had mean age 63.4 years and mean estimated glomerular filtration rate 31.4 +/- 12 mL/min. Aortic VC was present in 95% on CT, mean 564.9 +/- 304 Hounsfield units (HU). Aortic VC was seen in 68% on lateral DXA, mean scores 5.1 +/- 5.9 and 1.9 +/- 1.9 using 24- and 8-point scales, respectively. Strong correlation of VC measurement was present between CT and DXA (r 0.52, P < 0.001). For DXA VC 24-point score, intraclass correlations for intra-rater and inter-rater agreement were 0.91 and 0.64, respectively (8-point scale, intraclass correlations 0.90 and 0.69). Vertebral BMD measured by CT (mean 469.3 HU L2-4) also significantly correlated with lateral DXA-reported BMD (mean spine T-score -0.67 +/- 1.6) (r 0.56, P < 0.001).

CONCLUSION

Despite limitations in CKD, DXA may be useful as lateral DXA images provide concurrent assessment of aortic calcification as well as lumbar spine BMD, both correlating significantly with CT measurements. Lateral DXA may provide VC screening to determine patients at greater CV risk although more studies are needed to evaluate their potential role.

New fat free mass - fat mass model for use in physiological energy balance equations

Background

The Forbes equation relating fat-free mass (FFM) to fat mass (FM) has been used to predict longitudinal changes in FFM during weight change but has important limitations when paired with a one dimensional energy balance differential equation. Direct use of the Forbes model within a one dimensional energy balance differential equation requires calibration of a translate parameter for the specific population under study. Comparison of translates to a representative sample of the US population indicate that this parameter is a reflection of age, height, race and gender effects.

Results

We developed a class of fourth order polynomial equations relating FFM to FM that consider age, height, race and gender as covariates eliminating the need to calibrate a parameter to baseline subject data while providing meaningful individual estimates of FFM. Moreover, the intercepts of these polynomial equations are nonnegative and are consistent with observations of very low FM measured during a severe Somali famine. The models preserve the predictive power of the Forbes model for changes in body composition when compared to results from several longitudinal weight change studies.

Conclusions

The newly developed FFM-FM models provide new opportunities to compare individuals undergoing weight change to subjects in energy balance, analyze body composition for individual parameters, and predict body composition during weight change when pairing with energy balance differential equations.

Effect of alendronate on vascular calcification in CKD stages 3 and 4: a pilot randomized controlled trial

BACKGROUND

Vascular calcification contributes to cardiovascular disease in patients with chronic kidney disease (CKD). Few studies have addressed interventions to decrease vascular calcification; however, experimental studies report benefits of bisphosphonates. Recent studies of hemodialysis patients also suggest benefits of bisphosphonates on vascular calcification; however, no study exists in nondialysis patients with CKD.

STUDY DESIGN

We conducted a randomized controlled trial to determine the effect of bisphosphonates on vascular calcification in patients with CKD.

SETTING & PARTICIPANTS

51 patients with CKD stages 3-4 were recruited from a hospital outpatient setting; 50 were treated with study medication.

INTERVENTIONS

Patients were randomly assigned to either alendronate, 70 mg (n = 25), or matching placebo (n = 25), administered weekly.

OUTCOMES

The primary outcome was change in aortic vascular calcification after 18 months. Secondary outcomes included superficial femoral artery vascular calcification, arterial compliance, bone mineral density (BMD), renal function, and serum markers of mineral metabolism.

MEASUREMENTS

At baseline and 12 and 18 months, computed tomography, pulse wave velocity using SphygmoCor (AtCor Medical, PWV Inc, www.atcormedical.com), and dual-energy x-ray absorptiometry were performed to measure vascular calcification, arterial compliance, and BMD, respectively. Analysis was by intention to treat, with a random-effect linear regression model to assess differences.

RESULTS

46 patients completed the study (24 alendronate, 22 placebo); baseline mean age was 63.1 +/- 1.8 years, estimated glomerular filtration rate was 34.5 +/- 1.4 mL/min/1.73 m(2), 59% had diabetes, and 65% were men. 91% had aortic vascular calcification at the start and 78% showed progression. At 18 months, there was no difference in vascular calcification progression with alendronate compared with placebo (adjusted difference, -24.2 Hounsfield units [95% CI, -77.0 to 28.6]; P = 0.4). There was an increase in lumbar spine BMD (T score difference, +0.3 [95% CI, 0.03-0.6]; P = 0.04) and a trend toward better pulse wave velocity (-1 m/s [95% CI, -2.1 to 0.1]; P = 0.07) with alendronate. Femoral BMD was similar between groups. There was a nonsignificant decrease in kidney function in patients on alendronate therapy compared with placebo (-1.2 mL/min/1.73 m(2) [95% CI, -4.0 to 1.7]).

LIMITATIONS

Small sample size and baseline differences, especially with aortic vascular calcification, may have diminished any potential difference between groups.

CONCLUSIONS

Unlike previous studies of hemodialysis patients, alendronate did not decrease the progression of vascular calcification compared with placebo in patients with CKD during 18 months.

Calcium absorption in Australian osteopenic post-menopausal women: an acute comparative study of fortified soymilk to cows' milk

Calcium loss after menopause increases the risk of osteoporosis in aging women. Soymilk is often consumed to reduce menopausal symptoms, although in its native form, it contains significantly less calcium than cow's milk. Moreover, when calcium is added as a fortificant, it may not be absorbed efficiently. This study compares calcium absorption from soymilk fortified with a proprietary phosphate of calcium versus absorption from cow's milk. Preliminary studies compared methods for labelling the calcium fortificant either before or after its addition to soymilk. It was established that fortificant labelled after it was added to soymilk had a tracer distribution pattern very similar to that shown by fortificant labelled before adding to soymilk, provided a heat treatment (90?C for 30 min) was applied. This method was therefore used for further bioavailability studies. Calcium absorption from fortified soy milk compared to cow's milk was examined using a randomised single-blind acute cross-over design study in 12 osteopenic post-menopausal women aged (mean +/- SD) 56.7+/-5.3 years, with a body mass index of 26.5+/-5.6 kg/m2. Participants consumed 20 mL of test milk labelled after addition of fortificant with 185 kBq of 45Ca in 44 mg of calcium carrier, allowing the determination of the hourly fractional calcium absorption rate (alpha) using a single isotope radiocalcium test. The mean hourly fractional calcium absorption from fortified soymilk was found to be comparable to that of cows' milk: alpha = 0.65+/-0.19 and alpha =0.66+/-0.22, p>0.05, respectively.

Weight loss with liraglutide, a once-daily human glucagon-like peptide-1 analogue for type 2 diabetes treatment as monotherapy or added to metformin, is primarily as a result of a reduction in fat tissue

AIM

The effect on body composition of liraglutide, a once-daily human glucagon-like peptide-1 analogue, as monotherapy or added to metformin was examined in patients with type 2 diabetes (T2D).

METHODS

These were randomized, double-blind, parallel-group trials of 26 [Liraglutide Effect and Action in Diabetes-2 (LEAD-2)] and 52 weeks (LEAD-3). Patients with T2D, aged 18-80 years, body mass index (BMI) < or =40 kg/m(2) (LEAD-2), < or =45 kg/m(2) (LEAD-3) and HbA1c 7.0-11.0% were included. Patients were randomized to liraglutide 1.8, 1.2 or 0.6 mg/day, placebo or glimepiride 4 mg/day, all combined with metformin 1.5-2 g/day in LEAD-2 and to liraglutide 1.8, 1.2 or glimepiride 8 mg/day in LEAD-3. LEAD-2/3: total lean body tissue, fat tissue and fat percentage were measured. LEAD-2: adipose tissue area and hepatic steatosis were assessed.

RESULTS

LEAD-2: fat percentage with liraglutide 1.2 and 1.8 mg/metformin was significantly reduced vs. glimepiride/metformin (p < 0.05) but not vs. placebo. Visceral and subcutaneous adipose tissue areas were reduced from baseline in all liraglutide/metformin arms. Except with liraglutide 0.6 mg/metformin, reductions were significantly different vs. changes seen with glimepiride (p < 0.05) but not with placebo. Liver-to-spleen attenuation ratio increased with liraglutide 1.8 mg/metformin possibly indicating reduced hepatic steatosis. LEAD-3: reductions in fat mass and fat percentage with liraglutide monotherapy were significantly different vs. increases with glimepiride (p < 0.01).

CONCLUSION

Liraglutide (monotherapy or added to metformin) significantly reduced fat mass and fat percentage vs. glimepiride in patients with T2D.

Malnutrition on the menu: nutritional status of institutionalised elderly Australians in low-level care

BACKGROUND

Most studies reporting malnutrition in the elderly relate to high-level care. However, one third of Australians in aged care reside in low-level care facilities. Data is limited on their nutritional status.

OBJECTIVE

To investigate the nutritional status of elderly in low-level care facilities.

DESIGN

A cross sectional study design.

SETTING

14 low-level aged care facilities in metropolitan Melbourne.

PARTICIPANTS

Convenience sample of 103 ambulatory elderly (86 +/- 6.6 years (mean +/- SD), 76% female, comprising 15% of the hostel population) able to perform daily functions of living.

MEASUREMENTS

Nutritional intake assessed by three-day weighed food records, and nutritional status by haematological and biochemical markers and body composition (dual energy X-ray absorptiometry).

RESULTS

FOOD served did not supply the estimated average requirements (EAR) for 5 of the 14 nutrients analysed. Compared with EAR, 34% of participants were protein malnourished and 62% had energy intake deficits. Micronutrient intake was low for calcium, magnesium, folate, zinc (for men) and dietary fibre. Vitamin D deficiency (serum 25OH Vitamin D < 50 nmol/L) was present in 58% of residents. More men than women had low haemoglobin (P < 0.000), low red blood cells (P < 0.000), and a raised white blood cell count (P = 0.004). Forty three percent of men and 21% women had sarcopenia, 28% of men and 44% women had excess body fat (> 28% and >40%, respectively) and 14% of men and 12 % of women were sarcopenic-obese. Only 12% showed no sign of undernutrition using seven different nutritional indicators. Around 65% had two or more indicators of undernutrition.

CONCLUSION

These findings highlight the need for the supply of more, better quality, nutrient dense food to residents and better detection of undernutrition in aged care facilities. Maintenance of nutritional status has the potential to reduce morbidity and delay the transition to high-level care.

Body composition in home haemodialysis versus conventional haemodialysis: a cross-sectional, matched, comparative study

BACKGROUND

Nutritional status predicts outcome in dialysis populations. Increased dialysis time and/or frequency reportedly improves nutritional status. We examined the impact of more intensive dialysis on body composition.

METHODS

A cross-sectional, matched study comparing home haemodialysis (HHD) patients (>15 h/week, n = 28) and conventional haemodialysis (CHD) patients (<15 h/ week, n = 28), matched for age, sex, length of time on dialysis and diabetes, was performed. We measured total body protein (TBP) by in vivo neutron activation, total body fat (TBF) and skeletal muscle mass (SKMM) by dual-energy x-ray absorptiometry (DEXA) and biochemical and inflammatory parameters. Visceral (VFA) and subcutaneous fat areas (SFA) were determined from computed tomography.

RESULTS

There was no significant difference in TBP (10.2 +/- 1.9 kg CHD versus 10.8 +/- 1.8 kg HHD, P = 0.18) or SKMM (25.6 +/- 5.6 kg CHD versus 26.2 +/- 4.2 kg HHD). TBF was not different (27.7 +/- 10.7 kg CHD versus 27.8 +/- 16.0 kg HHD), although the HHD group had greater VFA (182.0 +/- 105.6 cm(2) versus 173.8 +/- 90.1 cm(2)) and lower SFA (306.7 +/- 176.4 cm(2) versus 309.7 +/- 138.1 cm(2)), the difference was not statistically significant. Albumin concentrations were significantly increased in the HHD group (37.5 +/- 3.56 g/L versus 35.18 +/- 4.11 g/L, P = 0.03), whilst phosphate concentrations (1.57 +/- 0.41 mmol/LHHD versus 1.92 +/- 0.62 mmol/ LCHD, P = 0.02) and inflammatory parameters were lower. There was a positive relationship between hours of dialysis and TBP (beta = 0.08; P = 0.03).

CONCLUSION

Surrogate nutritional markers and inflammatory parameters improved with more intensive dialysis, but this was not reflected by improved body composition. Further prospective studies are required to confirm whether more intensive dialysis affects body composition, and whether this impacts on metabolic risk and clinical outcome.