Chronic hypoparathyroidism is associated with increased cortical bone density evaluated using high-resolution peripheral quantitative computed tomography.

PURPOSE: This cross-sectional study aimed to assess bone mineral density (BMD), bone microarchitecture and fracture prevalence in women with chronic postsurgical hypoparathyroidism (hypoPT). METHODS: Twenty-seven women with postsurgical hypoPT and 44 age-matched healthy women were included. Dual-energy X-ray absorptiometry was used to evaluate areal BMD and vertebral fracture assessment. High-resolution peripheral quantitative computed tomography assessed microarchitecture and volumetric BMD at the distal radius and tibia. Biochemical parameters, including fibroblast growth factor 23, C-terminal cross-linking telopeptide of type I collagen (ICTP), and procollagen type I N-terminal propeptide (P1NP), were also measured. Previous low-impact fractures were assessed and the 10-year fracture risk was estimated using the FRAX tool for the Brazilian population. RESULTS: No participant had prevalent clinical fractures, and both groups showed low risk for major and hip based on FRAX tool, but two hypoPT patients had moderate to severe morphometric vertebral fractures. Women with hypoPT had increased aBMD in the lumbar spine, femoral neck and total hip (p < 0.05) and higher cortical vBMD in the radius (p = 0.020) and tibia (p < 0.001). Trabecular bone was not affected. Both P1NP and ICTP suggested low bone turnover rates, but no significant correlation was observed between bone density or microstructure and any of the biochemical parameters. CONCLUSIONS: The prevalence of fragility fractures was low in HypoPT women and compatible with low fracture risk estimated by the FRAX tool. Patients had a higher aBMD and cortical vBMD than those of healthy control women, but the association with decreased bone turnover remains unclear.

Lower bone density and microarchitecture alterations in HIV-infected Brazilian men aged 50 years and older are associated with estradiol levels.

OBJECTIVE: Combination antiretroviral treatment (cART) allows for longer survival for people living with HIV and hence long-term complications of both disease and treatment are common. Our purpose was to evaluate bone alterations in men living with HIV (MLWH) and receiving cART and to identify associated factors that can be corrected or mitigated. PATIENTS AND DESIGN: Thirty MLWH and 36 healthy controls (≥50 years) were studied for areal bone mineral density (aBMD) and body composition (dual-energy X-ray absorptiometry), volumetric bone mineral density (vBMD) and bone microstructure (high-resolution peripheral quantitative computed tomography [HR-pQCT]), serum calcium, phosphate, parathyroid hormone, 25(OH)D, testosterone (T), estradiol (E2 ), glucose, creatinine, and albumin levels. RESULTS: The proportion of patients classified as osteoporosis (according to the lowest aBMD T-score) was higher among MLWH as compared to controls (17.9% vs. 5.9%, p = .011). The MLWH showed significant alterations in cortical and trabecular bone on HR-pQCT, which were not associated with the duration of HIV infection or cART. These differences in vBMD and bone microstructure seen in HR-pQCT persisted in the nonosteoporotic MLWH as compared to nonosteoporotic control subjects. Body mass index (BMI) and fat mass were lower in MLWH and positively associated with total vBMD, cortical bone area, and thickness. E2 and E2 /T ratios were lower in MLWH than in controls and significantly correlated with several cortical and trabecular bone parameters. Multivariate regression analysis entering simultaneously age, BMI, and E2 defined that E2 is an independent influence on bone parameters evaluated by HR-pQCT. CONCLUSION: MLWH have alterations in bone volumetric density and microstructure when compared with controls, irrespective of aBMD, which are associated with lower E2 and BMI.

Bone Evaluation by High-Resolution Peripheral Quantitative Computed Tomography in Patients With Adrenal Incidentaloma.

CONTEXT: Data regarding high-resolution peripheral quantitative computed tomography (HR-pQCT) in patients with adrenal incidentaloma (AI) are unknown. PURPOSE: To evaluate the areal bone mineral density (aBMD), microstructure, and fractures in patients with nonfunctioning AI (NFAI) and autonomous cortisol secretion (ACS). METHODS: We evaluated 45 patients with NFAI (1 mg dexamethasone suppression test [DST] ≤1.8 µg/dL) and 30 patients with ACS (1 mg DST 1.9-5.0 µg/dL). aBMD was measured using dual-energy X-ray absorptiometry; vertebral fracture by spine X-ray; and bone geometry, volumetric bone mineral density (vBMD), and microstructure by HR-pQCT. RESULTS: Patients with ACS showed lower aBMD values at the spine, femoral neck, and radius 33% than those with NFAI. Osteoporosis was frequent in both groups: NFAI (64.9%) and ACS (75%). Parameters at the distal radius by HR-pQCT were decreased in patients with ACS compared to those with NFAI: trabecular vBMD (Tb.vBMD, P = 0.03), inner zone of the trabecular region (Inn.Tb.vBMD, P = 0.01), the bone volume/tissue volume ratio (BV/TV, P = 0.03) and trabecular thickness (P = 0.04). As consequence, a higher ratio of the outer zone of the trabecular region/inner zone vBMD (Meta/Inn.vBMD, P = 0.003) was observed. A correlation between the cortisol levels after 1 mg DST and Meta/Inn.vBMD ratio was found (r = 0.29; P = 0.01). The fracture frequency was 73.7% in patients with ACS vs 55.6% in patients with NFAI (P = 0.24). CONCLUSION: Our findings point to an association between trabecular bone microarchitectural derangement at the distal radius and ACS. Our data suggest that AI have a negative impact on bone when assessed by HR-pQCT, probably associated to subclinical hypercortisolism.

Bone mineral density and bone microarchitecture after long-term suppressive levothyroxine treatment of differentiated thyroid carcinoma in young adult patients.

Bone mineral density (BMD) seems not to be decreased in young patients given long-term suppressive doses of levothyroxine (LT4), but information regarding the bone microstructure in these patients is lacking. The aim of this study was to determine whether supraphysiologic doses of LT4, initiated during childhood or adolescence for treatment of differentiated thyroid carcinoma (DTC), have any detrimental effects on bone microarchitecture as evaluated by high-resolution peripheral quantitative computed tomography (HR-pQCT). Seventeen patients (27.3 ± 7.1 years old) with DTC with subclinical hyperthyroidism since adolescence and 34 healthy volunteers matched for age, sex, and body mass index were studied by dual-energy X-ray absorptiometry (DXA) to determine the areal BMD at the lumbar spine, hip, and proximal third of the radius. Volumetric BMD and structural parameters of the trabecular and cortical bone were assessed by HR-pQCT of the distal radius and distal tibia. DTC patients were given suppressive doses of LT4 starting at a mean age of 12.6 years, and the mean duration of treatment was 14.2 years. In DTC patients, clinical parameters did not correlate with DXA or HR-pQCT parameters. No differences were found between the patients and controls with respect to BMD and Z scores at any site evaluated by DXA, and no differences were found in the bone microstructure parameters evaluated by HR-pQCT. This cross-sectional study suggests that long-standing suppressive therapy with LT4 during the attainment of peak bone mass may have no significant adverse effects on bone density or microarchitecture.

Bone Mineral Density and Microarchitecture in Patients With Autosomal Dominant Osteopetrosis: A Report of Two Cases.

The aim of this case study is to describe changes in areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) scan, as well as volumetric bone density and microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT) in two patients with autosomal dominant osteopetrosis (ADO) and compare with 20 healthy subjects. We describe a 44-year-old male patient with six low-impact fractures since he was age 16 years, and a 32-year-old female patient with four low-impact fractures on her past history. Radiographic changes were typical of ADO. Consistent with the much higher aBMD, total volumetric BMD (average bone density of the whole bone, including trabecular and cortical compartments) at distal radius and tibia (HR-pQCT) was more than twice the mean values found in healthy subjects in both patients. Trabecular number and thickness were higher, leading to an evident increase in trabecular bone volume to tissue volume. Also, an enormous increase in cortical thickness was found. Most important, a great heterogeneity in bone microstructure of the affected patients was evident on HR-pQCT images: islets of very dense bone were interposed with areas with apparent normal density. The increase in aBMD, volumetric BMD, and most indices of trabecular and cortical bone, associated with the great heterogeneity on bone tridimensional microarchitecture, reflect the accumulation of old and fragile bone randomly distributed along the skeleton. These alterations in bone microstructure probably compromise bone quality, which might justify the high prevalence of low-impact fractures in patients with ADO, despite abnormally elevated BMD.

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.

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.