Laura Maria Carvalho de Mendonça

Acromegaly Has a Negative Influence on Trabecular Bone, But Not on Cortical Bone, as Assessed by High-Resolution Peripheral Quantitative Computed Tomography

INTRODUCTION Acromegaly is one of the causes of secondary osteoporosis, although studies of bone mineral density (BMD) have yielded conflicting results and none of them have evaluated the bone properties. OBJECTIVES AND PATIENTS Our objective was to correlate, in a cohort of 82 acromegalic patients, BMD and bone microarchitecture, using dual-energy x-ray absorptiometry and high-resolution peripheral quantitative computed tomography, with the presence of type 2 diabetes mellitus (T2DM), disease activity, and gonadal status and to compare these bone parameters between 45 eugonadal acromegalic patients and 45 healthy controls. RESULTS Acromegalic patients with T2DM had lower trabecular density and trabecular bone volume to tissue volume ratio in the distal tibia. Patients with active acromegaly exhibited a higher BMD and T-score in the lumbar spine (P = .02 for both) and a higher cortical density in the distal tibia when compared with those with controlled acromegaly (P = .001). After multiple linear regression (including age, presence of T2DM, acromegaly activity, and gonadal status), eugonadism remained the main determinant of bone parameters. The 45 acromegalic patients with eugonadism were compared with 45 age- and sex-matched controls and exhibited lower trabecular densities and impaired microstructures. CONCLUSIONS Acromegaly appears to have a deleterious effect on trabecular bone microarchitecture, and in this specific population, the gonadal status might be more important than T2DM or acromegaly activity in determining bone health. High-resolution peripheral quantitative computed tomography seems promising for evaluating acromegalic bone properties and for addressing the limitations posed by dual-energy x-ray absorptiometry.

Factors associated with low bone mineral density in a Brazilian cohort of vertically HIV-infected adolescents

OBJECTIVE To assess the prevalence and factors associated with low bone mineral density (BMD) in HIV-infected adolescents. METHODS This was a cross-sectional study of a Brazilian cohort of vertically HIV-infected adolescents. Body composition and lumbar spine (LS) and total body (TB) BMD were estimated by dual-energy X-ray absorptiometry (DXA). Low BMD was considered for a Z-score ≤-2 standard deviations. Pubertal development, anthropometric data, laboratory measurements, antiretroviral regimen, and time of immunological and virological recovery were evaluated as factors associated with a low BMD. RESULTS Seventy-four adolescents aged 17.3 ± 1.8 years were studied. Low BMD was present in 32.4% of them. LS and TB BMD Z-scores were positively correlated with weight, body mass index (BMI), BMI Z-score, total body fat, and nutritional status. Patients on tenofovir had lower LS and TB BMD Z-scores. Time on tenofovir was indirectly correlated with LS and TB BMD Z-scores. No difference was found regarding levels of calcium, parathyroid hormone, or 25-hydroxyvitamin D according to BMD status. CONCLUSIONS Control of the HIV infection, especially before the initiation of puberty, might have a positive influence on bone gain. Body composition and nutritional status had a positive influence on BMD that was more evident in females, suggesting that nutritional intervention may have a positive impact on BMD.

The prevalence of disordered eating and possible health consequences in adolescent female tennis players from Rio de Janeiro, Brazil

The aim of this study was to estimate the prevalence of disordered eating and possible health consequences in adolescent female tennis players. This cross-sectional controlled study investigated the pubertal development (Tanner stages); body composition (dual energy X-ray absorptiometry-DXA); dietary intake (food record); presence of disordered eating (EAT-26, BITE and BSQ); menstrual status (questionnaire) and bone mineral density (DXA). The Female Athlete Triad (FAT) was divided into two severity stages. The study included 45 adolescents (24 athletes and 21 controls) at some pubertal developmental stage. The athletes exhibited better body composition profiles. We found that 91.7%, 33.3% and 25% of athletes and 71.4%, 9.5% and 33.3% of controls met criteria for disordered eating and/or low energy availability, menstrual irregularities and low bone mass, respectively. A greater percentage of athletes than controls presented with 1 and 2 FAT components (stage I), and 4.2% presented with the full syndrome. In conclusion, tennis players appear to present with more severe disorders than controls and should be monitored to avoid damage to their performance and health.

Lean mass as a predictor of bone density and microarchitecture in adult obese individuals with metabolic syndrome

The effects of obesity and metabolic syndrome (MS) on bone health are controversial. Furthermore, the relationship between body composition and bone quality has not yet been determined in this context. The aim of this study was to investigate the correlations between body composition and bone mineral density (BMD) and bone microstructure in obese individuals with MS. This cross-sectional study assessed 50 obese individuals with MS with respect to their body composition and BMD, both assessed using dual X-ray absorptiometry, and bone microarchitecture, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal tibia and radius. Several HR-pQCT measurements exhibited statistically significant correlations with lean mass. Lean mass was positively correlated with parameters of better bone quality (r: 0.316-0.470) and negatively correlated with parameters of greater bone fragility (r: -0.460 to -0.310). Positive correlations were also observed between lean mass and BMD of the total femur and radius 33%. Fat mass was not significantly correlated with BMD or any HR-pQCT measurements. Our data suggest that lean mass might be a predictor of bone health in obese individuals with MS.

Risk Factors for Decreased Total Body and Regional Bone Mineral Density in Hemodialysis Patients With Severe Secondary Hyperparathyroidism

Hyperparathyroidism contributes significantly to decreased bone mineral density (BMD) in end-stage renal disease patients, but this negative influence is not homogeneous throughout the skeleton. We studied the BMD by dual-energy X-ray absorptiometry on total body and on different regions of the skeleton in 42 patients with severe hyperparathyroidism on hemodialysis. We also evaluated the relationship between different risk factors and BMD found on the regions examined in these patients. The legs and other sites where cortical bone predominate were mostly affected, whereas trabecular bone was relatively preserved. This is probably the result of the different effects of hyperparathyroidism on cortical and trabecular bone, but we cannot rule out the interference of ectopic calcifications and sclerotic lesions of vertebral end-plates falsely increasing lumbar spine BMD. The main determinants of low total-body BMD were, in order of importance, immobility, high intact parathyroid hormone levels, low body mass index, and low albumin. Eleven patients presented with pathologic fractures, mainly in the legs, and BMD was lower in this group than in patients without fractures. In conclusion, our study makes clear that hyperparathyroidism is a great threat to bone density in hemodialysis patients, mainly in the legs, the site mostly affected by fragility fractures in our patients. Physicians must worry not only with high parathyroid hormone levels, but also with the nutritional state of these patients.

Bone density and microarchitecture in endogenous hypercortisolism

Osteoporosis is a serious and underestimated complication of endogenous hypercortisolism that results in an increased risk of fractures, even in patients with normal or slightly decreased bone mineral density (BMD). Alterations in bone microarchitecture, a very important component of bone quality, may explain bone fragility. The aim of this study was to investigate bone density and microarchitecture in a cohort of patients with endogenous Cushings syndrome (CS).

Bone Density Is Directly Associated With Glomerular Filtration and Metabolic Acidosis but Do Not Predict Fragility Fractures in Men With Moderate Chronic Kidney Disease

Hyperparathyroidism, vitamin D deficiency, increased fibroblast growth factor-23 (FGF-23), and metabolic acidosis promote bone fragility in chronic kidney disease (CKD). Although useful in predicting fracture risk in the general population, the role of dual-energy X-ray absorptiometry (DXA) in CKD remains uncertain. This cross-sectional study included 51 men aged 50-75 yr with moderate CKD. The stage 4 CKD patients had higher levels of parathyroid hormone (p<0.001), FGF-23 (p=0.029), and lowest 25-hydroxyvitamin D (p=0.016), bicarbonate (p<0.001), total femur (p=0.003), and femoral neck (p=0.011) T-scores compared with stage 3 CKD patients. Total femur and femoral neck T-scores were directly correlated with serum bicarbonate (p=0.003, r=0.447 and p=0.005, r=0.427, respectively) and estimated glomerular filtration rate (p=0.024, r=0.325 and p=0.003, r=0.313, respectively) but were not significantly associated with parathyroid hormone, 25-hydroxyvitamin D, or FGF-23. Only 3.9% of the participants had osteoporosis on DXA scan, whereas 31.4% reported a low-impact fracture. Our data point to a pivotal role of metabolic acidosis for bone impairment and to the inadequacy of DXA to evaluate bone fragility in CKD patients.

Bone Mineral Density in Children and Adolescents with Congenital Adrenal Hyperplasia

Chronic glucocorticoid therapy is associated with reduced bone mineral density. In paediatric patients with congenital adrenal hyperplasia, increased levels of androgens could not only counteract this effect, but could also advance bone age, with interference in the evaluation of densitometry. We evaluate bone mineral density in paediatric patients with classic congenital adrenal hyperplasia taking into account chronological and bone ages at the time of the measurement. Patients aged between 5 and 19 years underwent radiography of the hand and wrist followed by total body and lumbar spine densitometry. Chronological and bone ages were used in the scans interpretation. In fourteen patients, mean bone mineral density Z-score of total body to bone age was −0.76 and of lumbar spine to bone age was −0.26, lower than those related to chronological age (+0.03 and +0.62, resp.). Mean Z-score differences were statistically significant (P = 0.004 for total body and P = 0.003 for lumbar spine). One patient was classified as having low bone mineral density only when assessed by bone age. We conclude that there was a reduction in the bone mineral density Z-score in classic congenital adrenal hyperplasia paediatric patients when bone age was taken into account instead of chronological age.

Análise de idosos ambulatoriais quanto ao estado nutricional, sarcopenia, função renal e densidade óssea

Objectives : To evaluate relationships between nutritional status, sarcopenia and osteoporosis in older women.Subjects and methods : We studied 44 women, 67-94 years, by mini-nutritional assessment (MAN), glomerular filtration corr. 1.73 m2, body mass index (BMI), arm circumference and calf (CP and CB), bone mineral density and body composition, DXA (fat mass MG; lean MM). We gauge sarcopenia: IMM MM = MSS + MIS/height2. We used the Pearson correlation coefficient, p < 0.05 as significant.Results : MNA and IMM were positively correlated with BMI, CP, CB and MG. Age influenced negatively FG corr., BMI, FM, IMM and CP. Fourteen had a history of osteoporotic fractures. The lowest T-score was directly related to MAN and MG.Conclusions The aging caused the decline of FG, fat mass and muscle; the calf circumference, and brachial reflected nutritional status and body composition; and major influences on BMD were nutritional status and fat mass.Arq Bras Endocrinol Metab. 2014;58(3):226-31

Impact of Weight Loss With Intragastric Balloon on Bone Density and Microstructure in Obese Adults

The historical concept that obesity protects against bone fractures has been questioned. Weight loss appears to reduce bone mineral density (BMD); however, the results in young adults are inconsistent, and data on the effects of weight loss on bone microstructure are limited. This study aimed to evaluate the impact of weight loss using an intragastric balloon (IGB) on bone density and microstructure. Forty obese patients with metabolic syndrome (mean age 35.1 ± 7.3 yr) used an IGB continuously for 6 mo. Laboratory tests, areal BMD, and body composition measurements via dual-energy X-ray absorptiometry, and volumetric BMD and bone microstructure measurements via high-resolution peripheral quantitative computed tomography were conducted before IGB placement and after IGB removal. The mean weight loss was 11.5%. After 6 mo, there were significant increases in vitamin D and carboxyterminal telopeptide of type 1 collagen levels. After IGB use, areal BMD increased in the spine but decreased in the total femur and the 33% radius. Cortical BMD increased in the distal radius but tended to decrease in the distal tibia. The observed trabecular bone loss in the distal tibia contributed to the decline in the total volumetric BMD at this site. There was a negative correlation between the changes in leptin levels and the measures of trabecular quality in the tibia on high-resolutionperipheral quantitative computed tomography. Weight loss may negatively impact bone microstructure in young patients, especially for weight-bearing bones, in which obesity has a more prominent effect.