Economic burden of patients with post-surgical chronic and transient hypoparathyroidism in the United States examined using insurance claims data

BACKGROUND

Hypoparathyroidism (HP) is a rare endocrine disease commonly caused by the removal or damage of parathyroid glands during surgery and resulting in transient (tHP) or chronic (cHP) disease. cHP is associated with multiple complications and comorbid conditions; however, the economic burden has not been well characterized. The objective of this study was to evaluate the healthcare resource utilization (HCRU) and costs associated with post-surgical cHP, using tHP as a reference.

METHODS

This analysis of a US claims database included patients with both an insurance claim for HP and thyroid/neck surgery between October 2014 and December 2019. cHP was defined as an HP claim ≥ 6 months following surgery and tHP was defined as only one HP claim < 6 months following surgery. The cHP index date was the first HP diagnosis claim following their qualifying surgery claim, whereas the tHP index date was the last HP diagnosis claim following the qualifying surgery claim. Patients were continuously enrolled at least 1 year pre- and post-index. Patients' demographic and clinical characteristics, all-cause HCRU, and costs were descriptively analyzed. Total all-cause costs were calculated as the sum of payments for hospitalizations, emergency department, office/clinic visits, and pharmacy.

RESULTS

A total of 1,406 cHP and 773 tHP patients met inclusion criteria. The average age (52.1 years cHP, 53.5 years tHP) and representation of females (83.2% cHP, 81.2% tHP) were similar for both groups. Neck dissection surgery was more prevalent in cHP patients (23.6%) than tHP patients (5.3%). During the 1-2 year follow-up period, cHP patients had a higher prevalence of inpatient admissions (17.4%), and emergency visits (26.0%) than the reference group -tHP patients (14.4% and 21.4% respectively). Among those with a hospitalization, the average number of hospitalizations was 1.5-fold higher for cHP patients. cHP patients also saw more specialists, including endocrinologists (28.7% cHP, 15.8% tHP), cardiologists (16.7% cHP, 9.7% tHP), and nephrologists (4.6% cHP, 3.3% tHP).

CONCLUSION

This study demonstrates the increased healthcare burden of cHP on the healthcare system in contrast to patients with tHP. Effective treatment options are needed to minimize the additional resources utilized by patients whose HP becomes chronic.

Risk of wrist fracture, estimated by the load-to-strength ratio, declines following sleeve gastrectomy in adolescents and young adults

To understand whether the bone loss which occurs after vertical sleeve gastrectomy increases the risk of fracture, we used an engineering model to estimate risk in participants before and after surgery. We found that estimated risk decreased 1 year after surgery and remained lower, though had rebounded, at year 2.

PURPOSE

Vertical sleeve gastrectomy (VSG) improves metabolic health in young people with obesity but is accompanied by substantial loss of bone mass and estimated bone strength. We thus estimated fracture risk following VSG using the load-to-strength ratio (LSR), which integrates bone strength estimates with the predicted force of a fall.

METHODS

Prospective 2-year study of youth ages 13-24 years with obesity undergoing VSG (n = 24) or lifestyle therapy (n = 34). We performed high-resolution peripheral quantitative computed tomography of the distal radius and microfinite element analysis to estimate bone strength and calculated LSR.

RESULTS

VSG participants lost 26.4 ± 8.1% weight at year 1 (p < 0.001), which was sustained at year 2, while control participants gained weight at year 2 (4.5 ± 8.3%, p = 0.009). The predicted impact force decreased at years 1 and 2 following VSG (p < 0.001) but increased at year 2 among controls (p = 0.011). Estimated bone strength was unchanged at year 1 but decreased (p < 0.001) at year 2 following VSG, while bone strength did not change in controls. At year 1, the LSR decreased among VSG participants (p < 0.001), implying a lower risk of fracture. At year 2, the LSR was lower than baseline (p < 0.001), but higher compared to year 1 (p = 0.001). LSR did not change in the control group.

CONCLUSIONS

Short-term estimated fracture risk at the radius following VSG decreases. However, ongoing bone loss despite stable weight between years 1 and 2 leads to a concerning rise in estimated fracture risk. Longer follow-up will be critical to evaluate the trajectory of fracture risk. (ClinicalTrials.gov NCT02557438, registered 9/23/2015).

Total Calcium Intake Is Associated With Trabecular Bone Density in Adolescent Girls With Type 1 Diabetes

Type 1 diabetes (T1D) confers an increased risk of fracture and is associated with lower bone mineral density (BMD) and altered microarchitecture compared with controls. Adequate calcium (Ca) intake promotes bone mineralization, thereby increasing BMD. The objective of this analysis was to evaluate the associations of total daily Ca intake with bone outcomes among youth with T1D. This was a cross-sectional analysis of girls ages 10-16 years with (n = 62) and without (n = 60) T1D. We measured Ca intake with a validated food-frequency questionnaire and BMD, microarchitecture, and strength estimates with dual-energy X-ray absorptiometry and high-resolution peripheral quantitative computed tomography. Total daily Ca intake did not differ between groups (950 ± 488 in T1D versus 862 ± 461 mg/d in controls, p = 0.306). Serum 25OHD was lower in T1D (26.3 ± 7.6 versus 32.6 ± 9.0 ng/mL, p = <0.001), and parathyroid hormone (PTH) was higher in T1D (38.9 ± 11 versus 33.4 ± 9.7 pg/mL, p = 0.004). Trabecular volumetric BMD and thickness at the tibia were lower in T1D (p = 0.013, p = 0.030). Ca intake correlated with trabecular BMD at the radius and tibia among T1D participants (β = 0.27, p = 0.047, and β = 0.28, p = 0.027, β = 0.28, respectively) but not among controls (pinteraction = 0.009 at the radius, pinteraction = 0.010 at the tibia). Similarly, Ca intake was associated with estimated failure load at the tibia in T1D but not control participants (p = 0.038, β = 0.18; pinteraction = 0.051). We observed the expected negative association of Ca intake with parathyroid hormone in controls (p = 0.022, β = -0.29) but not in T1D participants (pinteraction = 0.022). Average glycemia as measured by hemoglobin A1c did not influence the relationship of Ca and PTH among participants with T1D (pinteraction = 0.138). These data suggest that youth with T1D may be particularly vulnerable to dietary Ca insufficiency. Increasing Ca intake may be an effective strategy to optimize bone health in this population. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Bone changes post-sleeve gastrectomy in relation to body mass and hormonal changes

OBJECTIVE

To determine mechanisms contributing to impaired bone health in youth 24 months following sleeve gastrectomy (SG).

DESIGN

Twenty-four-month longitudinal observational study.

METHODS

Participants included 23 youth undergoing SG and 30 non-surgical controls (NS) 13-25 years old with moderate-to-severe obesity. Subjects underwent fasting labs for bone turnover markers (N-terminal propeptide of type 1 procollagen, C-telopeptide (CTX)), sex hormones, sex hormone binding globulin (SHBG), and enteric peptides, DXA for areal bone mineral density (aBMD) and body composition, high-resolution peripheral quantitative CT for volumetric BMD (vBMD) at the distal radius and tibia, and microfinite element analysis for strength estimates.

RESULTS

Groups did not differ for mean age or BMI z-scores. Over 24 months, compared to NS, SG had greater reductions in BMI z-scores, and spine, hip, and femoral neck aBMD Z-scores (P ≤ .012), greater increases in serum CTX and SHBG (P ≤ .039), and greater decreases in estrone and ghrelin (P ≤ .021). Among females, estrone and free androgen index (FAI) decreased (P ≤ .022) in SG vs NS groups. After controlling for age and sex, decreases in BMI and lean mass were associated with decreases in total hip and femoral neck aBMD Z-scores, and decreases in radial total and trabecular vBMD and failure load, and tibial total and trabecular vBMD. Among females, after controlling for age, decreases in estrone were associated with decreases in spine aBMD Z-scores and radial total and trabecular vBMD, and decrease in FAI with decreases in radial failure load.

CONCLUSION

Reductions in BMI, lean mass, and sex steroids over 24 months post-SG are associated with bone loss and could be targeted for preventative or therapeutic interventions. Clinical trial registration number: The study is registered in ClinicalTrials.gov (NCT02557438).

Skeletal Effects of Sleeve Gastrectomy in Adolescents and Young Adults: A 2-Year Longitudinal Study

CONTEXT

Vertical sleeve gastrectomy (VSG) is an increasingly common tool to achieve weight loss and improve metabolic health in adolescents and young adults with obesity, although it may adversely affect bone health.

OBJECTIVE

This work aimed to evaluate the effect of VSG on bone health in youth.

METHODS

An observational 2-year study was conducted at a tertiary care center of 66 patients aged 13 to 24 years with moderate-to-severe obesity meeting criteria for VSG. The patients underwent VSG (n = 30) or nonsurgical (n = 36) management per the decision of patient and clinical team. Main outcome measures included dual-energy x-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HRpQCT) measures of bone mineral density (BMD), geometry, and microarchitecture.

RESULTS

VSG patients achieved 25.3 ± 2.0% weight loss at 2 years (P < .001) while control subjects gained 4.0 ± 2.0% (P = .026). Total hip BMD declined 8.5 ± 1.0% following VSG compared with 0.1 ± 1.0% gain in controls (P < .001), with similar results at the femoral neck (P < .001). Total volumetric BMD (vBMD) decreased both at the distal radius and tibia following VSG (P < .001) driven primarily by trabecular vBMD loss (P < .001). Two-year changes in cortical vBMD did not differ between groups, though cortical porosity decreased following VSG both at the radius and tibia (P = .048 and P < .001). Cortical thickness increased in controls but not in VSG (P = .022 and P = .002 for between-group comparisons at the radius and tibia, respectively). Following VSG, estimated failure load decreased at the radius and did not demonstrate the physiologic increases at the tibia observed in controls.

CONCLUSION

VSG leads to progressive changes in bone health over 2 years, and may lead to increased skeletal fragility in adolescents and young adults.

Epidemiology and Financial Burden of Adult Chronic Hypoparathyroidism

Chronic hypoparathyroidism is characterized by low serum calcium, increased serum phosphorus, and inappropriately low or decreased serum parathyroid hormone. This rare disorder is associated with a variety of complications. The prevalence, incidence, mortality, financial burden, and epidemiology of complications of this disorder are not well understood. This narrative review summarizes current information on the epidemiology and complications of chronic hypoparathyroidism. The reported prevalence of chronic hypoparathyroidism ranges from 6.4-37/100,000, and the incidence is reported to be 0.8-2.3/100,000/year. Mortality is not increased in studies from Denmark or South Korea but was increased in studies from Scotland and Sweden. The financial burden of this disorder is substantial because of increased health care resource utilization in two studies but not well quantitated. Recognized complications include hypercalciuria, nephrocalcinosis, kidney stones, and chronic kidney disease; low bone turnover and possibly upper extremity fractures; cardiac and vascular calcifications; basal ganglia calcifications, cataracts, infections, neuropsychiatric complications, and difficulties with pregnancy. This review concludes that chronic hypoparathyroidism is a rare disorder associated with significant morbidity that may not increase overall mortality but is associated with a substantial financial burden. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Load-to-strength ratio at the radius is higher in adolescent and young adult females with obesity compared to normal-weight controls

BACKGROUND

Among adolescents with extremity fractures, individuals with obesity have greater representation compared with individuals of normal-weight, despite having higher areal and volumetric bone mineral density (aBMD, vBMD) than their normal-weight counterparts. The relative increase in BMD in individuals with obesity may thus be insufficient to support the greater force generated upon falling. The load-to-strength ratio is a biomechanical approach for assessing the risk of fracture by comparing applied force to bone strength, with higher load-to-strength ratios indicating higher fracture risk.

OBJECTIVE

To assess the load-to-strength ratio at the distal radius in adolescent and young adult females with severe obesity (OB) compared with normal-weight healthy controls (HC). We hypothesized that OB have a higher load-to-strength ratio compared to HC.

METHODS

We examined bone parameters in 65 girls 14-21 years old: 33 OB and 32 HC. We used dual-energy X-ray absorptiometry (DXA) to assess body composition, high resolution peripheral quantitative CT (HR-pQCT) to estimate vBMD, and microfinite element analysis (μFEA) to assess bone strength at the distal radius. To quantify fracture risk, we computed the load-to-strength ratio, where the numerator is defined as the load applied to the outstretched hand during a forward fall and the denominator is the bone strength, as estimated by μFEA.

RESULTS

Although OB had higher total vBMD than HC (368.3 vs. 319.9 mgHA/cm3, p = 0.002), load-to-strength ratio at the radius was greater in OB than HC after controlling for age and race (0.66 vs. 0.54, p < 0.0001). In OB, impact force and load-to-strength ratio were associated negatively with % lean mass (r = -0.49; p = 0.003 and r = -0.65; p < 0.0001 respectively) and positively with visceral fat (r = 0.65; p < 0.0001 and r = 0.36; p = 0.04 respectively).

CONCLUSIONS

Adolescent and young adult females with obesity have higher load-to-strength ratio at the distal radius due to higher forces applied to bone in a fall combined with incomplete adaptation of bone to increasing body weight. This is differentially affected by lean mass, fat mass, and visceral fat mass.

Report of Prolonged Neonatal Hypoglycemia in Three Infants of Mothers With Variants in HNF1A

Background/Objective

Genetic variants in hepatic nuclear factor 1α (HNF1A) cause maturity-onset diabetes of the young (MODY). We sought to examine whether HNF1A MODY variants also cause neonatal hypoglycemia.

Case Report

We present 3 infants with variants in HNF1A shared with their mothers. The infants experienced neonatal hypoglycemia, 2 extending beyond 1 year and the third resolving by 28 days, and all were large for gestational age (birth weights of >99th percentile). In 2 cases, genetic testing for neonatal hypoglycemia revealed pathogenic variants in HNF1A; 1 mother was previously diagnosed with HNF1A MODY, and the other's genetic testing and ultimate MODY diagnosis were prompted by her child's hypoglycemia workup. In the third case, the infant's persistent hypoglycemia prompted genetic testing, revealing an HNF1A variant of uncertain significance, which was then identified in the mother.

Discussion

Genetic variants causing HNF1A MODY have not been definitively linked to neonatal hypoglycemia or fetal overgrowth in utero. MODY caused by HNF1A is clinically similar to that caused by HNF4A, for which a causal relationship with neonatal hypoglycemia is more certain. Case reports have previously implicated variants in HNF1A in congenital hyperinsulinism; however, these cases have generally not been in families with MODY. The cases presented here suggest that HNF1A variants causing MODY may also cause neonatal hypoglycemia.

Conclusion

Although confounding factors make the assessment of neonatal hypoglycemia challenging, these cases offer potential support for single genetic variants in HNF1A causing both MODY and neonatal hypoglycemia, with associated fetal overgrowth in utero.

Changes in Sex Steroids and Enteric Peptides After Sleeve Gastrectomy in Youth in Relation to Changes in Bone Parameters

CONTEXT

Sleeve gastrectomy (SG) improves metabolic endpoints but is associated with impaired bone outcomes.

OBJECTIVE

To determine mechanisms contributing to impaired bone health in youth following SG.

METHODS

12-month longitudinal observational study in a multidisciplinary tertiary-care hospital, including 64 youth 13-25 years old with moderate-to-severe obesity (51 females); 30 underwent SG and 34 were nonsurgical (NS) controls. SG was undertaken after a combined decision-making process between treatment team and patient. The main outcome measures were fasting blood for enteric peptides, sex steroids, sclerostin, and bone turnover markers (N-terminal propeptide of type 1 procollagen [P1NP] and C-terminal cross-linking telopeptide [CTX]); dual-energy X-ray absorptiometry measures of areal bone mineral density (aBMD) and body composition; high resolution peripheral quantitative computed tomography; measures of volumetric BMD (vBMD); microfinite element analysis of strength estimates (distal radius and tibia).

RESULTS

SG had greater reductions in body mass index (BMI) z-scores, serum estrone, and the free androgen index (FAI) (P ≤ .046), and greater increases in sclerostin, P1NP, and CTX (P ≤ .010) than NS controls. Fasting ghrelin decreased in SG vs NS (P < .0001); fasting peptide YY did not change. Most changes were driven by female SG participants. Among females (the majority of study participants), after controlling for baseline age and race, reductions in total hip aBMD Z-scores were positively associated with changes in BMI, lean mass, estrone, FAI, and ghrelin, and inversely with changes in sclerostin.. Decreases in total vBMD of the radius and tibia were associated positively with decreases in BMI. Increases in CTX were associated with decreases in BMI, lean mass, and ghrelin, and increases in sclerostin.

CONCLUSION

Bone loss after SG in youth is associated with changes in body composition, sex steroids, sclerostin, and enteric peptides. These are potential targets for future preventative or therapeutic strategies.

Impact of sleeve gastrectomy on bone outcomes in adolescents vs. adults with obesity

BACKGROUND

Sleeve gastrectomy (SG) is the most common metabolic and bariatric surgery (MBS) procedure in adolescents and adults. Only few studies have assessed bone outcomes following SG and it is unknown whether skeletal changes differ by age group. Recent studies have identified marrow adipose tissue (MAT) as a novel biomarker for bone quality with studies in adults showing high MAT in those with visceral adiposity and a reciprocal increase in MAT with bone loss.

OBJECTIVE

To determine the impact of SG on volumetric BMD (vBMD) and MAT in adolescents and adults with obesity. We hypothesized that SG would lead to a decrease in vBMD and increase in MAT but that these changes would be less pronounced in adolescents compared to adults.

MATERIALS AND METHODS

The study was IRB-approved and HIPAA-compliant. Written informed consent/assent was obtained. We examined 10 adolescents (mean age 17.8 ± 2.5 years, mean BMI 43.5 ± 5.6 kg/m²) and 10 sex, race, and BMI-matched adults (mean age 49.5 ± 13.6 years, mean BMI 43.7 ± 5.9 kg/m²), before and 12 months after SG. At baseline and 12 months, subjects underwent quantitative CT of the lumbar spine (L1-L2) to assess trabecular vBMD, single voxel proton MR spectroscopy at 3 T (PRESS pulse sequence without water suppression) at L1-L2 to quantify MAT, and MRI of the abdomen to assess visceral (VAT) and subcutaneous adipose tissue (SAT).

RESULTS

At baseline, adolescents had lower MAT (p = 0.0002) and higher vBMD (p = 0.050) compared to adults. Adolescents and adults lost 27.9 ± 6.5 vs. 25.0 ± 11.2% of body weight (p < 0.0001 for within group change), while there was no significant difference between groups (p = 0.455). There was a significant reduction in vBMD in adults (-3.9 ± 3.9%, p = 0.005) and a trend for a reduction in adolescents (-3.7 ± 7.5%, p = 0.119), with no significant difference between groups (p = 0.944). Lumbar MAT content increased in both adults and adolescents (p ≤ 0.034), while the difference was not significant between groups (p = 0.281). In adolescents and adults, 12-month percent change in weight and BMI was positively associated with % change in MAT (p ≤ 0.042). 12-month percent change in MAT was positively associated with 12-month % change in SAT in adolescents and 12-month percent change in VAT in adults (p ≤ 0.045).

CONCLUSION

SG in adolescents and adults with severe obesity is associated with a reduction in lumbar vBMD and an increase in lumbar MAT, although the reduction in adolescents did not reach statistical significance, with no significant differences in these endpoints between groups. Our results suggest detrimental effects of bariatric surgery on bone for patients across the life span.

Clinical Burden and Practice Patterns in Patients With Chronic Hypoparathyroidism in the United States (US): A Claims Data Analysis Using Diagnosis-Based Criteria

Objectives: Significant knowledge gaps exist regarding the comorbidities, treatment and lab testing patterns of patients with chronic hypoparathyroidism (cHP). This study describes a large cohort of patients with cHP identified using a diagnosis-based criteria from a claims database.

Methods: This retrospective cohort study was conducted using a large (130 million individuals) claims database (HealthVerity Closed Payer Claim Medical and Pharmacy databases: Private Source 20) from Oct 2014 to Dec 2019. Eligible patients had ≥2 diagnosis claims of HP (ICD9/10 codes: E20.0, E20.8, E20.9, 252.1) that were 6–15 months apart, a prescription claim for either active vitamin D, calcium, PTH or thyroid replacement therapy between the first qualifying HP claim and within 30 days of the second HP claim, and continuous enrollment for one year before the index date (the date of the first of two qualifying HP diagnosis claims) and ≥16 months after. Patients were followed up to two years after the index date. Patient characteristics, comorbidities, lab testing and treatment patterns were descriptively analyzed.

Results: Out of 43,640 patients with a diagnosis claim for HP, 4,118 patients met the eligibility criteria. The mean age of the cohort was 56.5 years + 18.6 (SD), and 76.4% were females, similar to data from other large cohort studies. The most common comorbidities during the 1-year follow-up were hypertension (56.0%), hypocalcemia (38.7%), cancer (30.5%, of which 24% were thyroid cancers), diabetes (29.4%), chronic pulmonary disease (24.1%), cardiac arrhythmias (17.4%), CKD stage 3–5 (17.0%), osteoporosis (9.6%) and neuropsychiatric disorders, including depressive disorders (22.0%), anxiety (21.6%), and sleep-wake disorders (18.4%). During the 1-year follow up, commonly monitored lab tests included serum calcium (89.9%), eGFR/creatinine (85.7%), 25-hydroxy vitamin D (61.1%), and intact PTH (43.9%). Remarkably, serum phosphorous (36.3%), serum magnesium (35.4%), and 24h-urine calcium (10.5%) were much less often monitored. In addition, BMD was measured in 10.9% patients. Also during the 1-year follow-up, 67.1% of patients had a prescription claim for thyroid replacement therapy, 60.5% for calcitriol, 15.7% for ergocalciferol, and 3.4 % for PTH.

Conclusion: Findings from this study highlight the high comorbidity burden in cHP patients which aligns with the monitoring patterns. Kidney function appears to be a key concern and may be important when considering therapeutic intervention. The comorbidities and practice patterns observed in this study are consistent with the results obtained using a surgery-based approach to identify cHP patients in the same claims database. Future studies will also examine the economic burden of cHP.

Clinical Burden and Practice Patterns in Patients With Chronic Hypoparathyroidism in the United States (US): A Claims Data Analysis Using Surgery-Based Criteria

Objectives: Significant knowledge gaps exist regarding the clinical burden and practice patterns associated with chronic hypoparathyroidism (cHP). This study assessed the clinical burden and practice patterns in patients with cHP identified using surgery-based criteria.

Methods: This retrospective cohort study was conducted using a large (130 million individuals) US claims database, the HealthVerity Closed Payer Claim Medical and Pharmacy database (Private Source 20) from Oct 2014 to Dec 2019. The patient eligibility criteria for the surgery-based method included the presence of a procedure claim of either parathyroidectomy, complete or partial thyroidectomy, or neck dissection, followed by a HP diagnosis claim (6–15 months apart) with a subsequent second HP diagnosis claim at any time point, and with continuous enrollment for 15 months before the index date (the date of the first qualifying HP diagnosis claim) and ≥6 months after. Patients were followed one year before the surgery and up to two years after the index date. Patient characteristics, comorbidities, laboratory testing and treatment patterns were descriptively analyzed.

Results: A total of 1,406 patients met the eligibility criteria, among which 1,184 patients had complete data for 1-year follow-up. The mean age was 52.1 + 16.4 (SD) years, and 83.2% were females. The mean time between surgery and qualifying HP diagnosis claim was 8.7 + 2.3 (SD) months, and 115 patients (8.2%) had a HP diagnosis prior to surgery. During the 1-year follow-up, the most common comorbidities were cancer (54.2%, of which 49% were thyroid cancers), hypertension (49.7%), hypocalcemia (47.1%), chronic pulmonary disease (21.9%), diabetes (21.7%), cardiac arrhythmias (18.4%), CKD stage 3–5 (11.3%), osteoporosis (9.8%), and neuropsychiatric disorders, including anxiety (23.9%), depressive disorders (21.8%), and sleep-wake disorders (20.9%). Most cHP patients were monitored for lab values. These included serum calcium (93.2%), eGFR/creatinine (86.2%), 25-Hydroxy Vitamin D (66.5%), intact PTH (63.0%), serum magnesium (40.9%), serum phosphorous (38.4%), bone mineral density (9.8%), and 24h-urine calcium (8.4%) during the 1-year follow up. Also within the 1-year follow-up, 66.9% of patients had a prescription claim for thyroid replacement therapy, 51.6% for calcitriol, 13.3% for ergocalciferol, and 5.5 % for PTH.

Conclusion: This cHP population, identified using surgery-based criteria, largely consists of patients with a recent diagnosis, and had a substantial comorbidity burden that aligned with the monitoring patterns. Already at this early stage of cHP, kidney function appears to be a key concern and may be important when considering therapeutic intervention. These data are consistent with our findings from a larger cHP population identified in the same database using a diagnosis-based approach.

Hip Structural Analysis Reveals Impaired Hip Geometry in Girls With Type 1 Diabetes

CONTEXT

Among patients with type 1 diabetes (T1D), the risk of hip fracture is up to 6-fold greater than that of the general population. However, the cause of this skeletal fragility remains poorly understood.

OBJECTIVE

To assess differences in hip geometry and imaging-based estimates of bone strength between youth with and without T1D using dual-energy x-ray absorptiometry (DXA)-based hip structural analysis.

DESIGN

Cross-sectional comparison.

PARTICIPANTS

Girls ages 10 to 16 years, including n = 62 with T1D and n = 61 controls.

RESULTS

The groups had similar age, bone age, pubertal stage, height, lean mass, and physical activity. Bone mineral density at the femoral neck and total hip did not differ in univariate comparisons but was lower at the femoral neck in T1D after adjusting for bone age, height, and lean mass. Subjects with T1D had significantly lower cross-sectional area, cross-sectional moment of inertia, section modulus, and cortical thickness at the narrow neck, with deficits of 5.7% to 10.3%. Cross-sectional area was also lower at the intertrochanteric region in girls with T1D. Among those T1D subjects with HbA1c greater than the cohort median of 8.5%, deficits in hip geometry and strength estimates were more pronounced.

CONCLUSIONS

DXA-based hip structural analysis revealed that girls with T1D have unfavorable geometry and lower estimates of bone strength at the hip, which may contribute to skeletal fragility and excess hip fracture risk in adulthood. Higher average glycemia may exacerbate effects of T1D on hip geometry.

Elevated HbA1c Is Associated with Altered Cortical and Trabecular Microarchitecture in Girls with Type 1 Diabetes

CONTEXT

Skeletal fragility is a significant complication of type 1 diabetes (T1D), with an increased risk of fracture observed starting in childhood. Altered bone accrual and microarchitectural development during the critical peripubertal years may contribute to this fragility.

OBJECTIVE

To evaluate differences in skeletal microarchitecture between girls with T1D and controls and to assess factors associated with these differences.

DESIGN

Cross-sectional comparison.

PARTICIPANTS

Girls ages 10-16 years, 62 with T1D and 61 controls.

RESULTS

Areal bone mineral density (BMD) measured by dual-energy x-ray absorptiometry did not differ between girls with and without T1D. At the distal tibia, trabecular BMD was 7.3 ± 2.9% lower in T1D (P = 0.013), with fewer plate-like and axially-aligned trabeculae. Cortical porosity was 21.5 ± 10.5% higher, while the estimated failure load was 4.7 ± 2.2% lower in T1D (P = 0.043 and P = 0.037, respectively). At the distal radius, BMD and microarchitecture showed similar differences between the groups but did not reach statistical significance. After stratifying by HbA1c, only those girls with T1D and HbA1c > 8.5% differed significantly from controls. P1NP, a marker of bone formation, was lower in T1D while CTX and TRAcP5b, markers of bone resorption and osteoclast number, respectively, did not differ. The insulin-like growth factor 1 (IGF-1) Z-score was lower in T1D, and after adjustment for the IGF-1 Z-score, associations between T1D status and trabecular microarchitecture were largely attenuated.

CONCLUSIONS

Skeletal microarchitecture is altered in T1D early in the course of disease and among those with higher average glycemia. Suppressed bone formation and lower circulating IGF-1 likely contribute to this phenotype.

Temporal increases in 25-hydroxyvitamin D in midlife women: Longitudinal results from the Study of Women's Health Across the Nation

OBJECTIVE

25-hydroxyvitamin D (25(OH)D) is critical for bone mineralization and may prevent fractures. Understanding vitamin D deficiency trends in midlife women is particularly important given their concurrent menopausal changes that increase risk for fracture. We aimed to evaluate changes in mean 25(OH)D over time and their determinants in a racially, ethnically and socioeconomically diverse cohort of midlife women.

DESIGN

A multi-centre prospective cohort study.

PATIENTS

1585 women ages 42-52 years at baseline.

MEASUREMENTS

We measured serum 25(OH)D at 2 time points (1998-2000 and 2009-2011). Between-visit change was assessed in the whole cohort and in socioeconomic and demographic subgroups. Among those with vitamin D deficiency (25(OH)D <30 nmol/L) at baseline, we evaluated determinants of persistent deficiency at follow-up.

RESULTS

Mean 25(OH)D increased from 53.8 to 70.0 nmol/L (P < 0.001), and the prevalence of deficiency decreased from 20.4% to 9.7% (P < 0.001). While baseline 25(OH)D differed among subgroups, the changes in 25(OH)D were similar among groups. The proportion of women reporting dietary supplement use increased from 40.8% to 67.1% (P < 0.001), and the increase in 25(OH)D was significantly higher in supplement users. Among women with vitamin D deficiency at baseline, White women and supplement users were less likely to remain deficient at follow-up.

CONCLUSIONS

Among midlife women, temporal increases in 25(OH)D concentrations are driven largely by increases in supplement use. The proportion of women with 25(OH)D <30 nmol/L and thus at high risk for skeletal consequences remains substantial. Targeted screening for vitamin D deficiency in populations at risk for fragility fracture may be advisable.

Validation of a Metastatic Assay using biopsies to improve risk stratification in patients with prostate cancer treated with radical radiation therapy

Background

Radiotherapy is an effective treatment of intermediate/high-risk locally advanced prostate cancer, however, >30% of patients relapse within 5 years. Clinicopathological parameters currently fail to identify patients prone to systemic relapse and those whom treatment intensification may be beneficial. The purpose of this study was to independently validate the performance of a 70-gene Metastatic Assay in a cohort of diagnostic biopsies from patients treated with radical radiotherapy and androgen deprivation therapy.

Patients and methods

A bridging cohort of prostate cancer diagnostic biopsy specimens was profiled to enable optimization of the Metastatic Assay threshold before further independent clinical validation in a cohort of diagnostic biopsies from patients treated with radical radiotherapy and androgen deprivation therapy. Multivariable Cox proportional hazard regression analysis was used to assess assay performance in predicting biochemical failure-free survival (BFFS) and metastasis-free survival (MFS).

Results

Gene expression analysis was carried out in 248 patients from the independent validation cohort and the Metastatic Assay applied. Ten-year MFS was 72% for Metastatic Assay positive patients and 94% for Metastatic Assay negative patients [HR = 3.21 (1.35–7.67); P = 0.003]. On multivariable analysis the Metastatic Assay remained predictive for development of distant metastases [HR = 2.71 (1.11–6.63); P = 0.030]. The assay retained independent prognostic performance for MFS when assessed with the Cancer of the Prostate Assessment Score (CAPRA) [HR = 3.23 (1.22–8.59); P = 0.019] whilst CAPRA itself was not significant [HR = 1.88, (0.52–6.77); P = 0.332]. A high concordance [100% (61.5–100)] for the assay result was noted between two separate foci taken from 11 tumours, whilst Gleason score had low concordance.

Conclusions

The Metastatic Assay demonstrated significant prognostic performance in patients treated with radical radiotherapy both alone and independent of standard clinical and pathological variables. The Metastatic Assay could have clinical utility when deciding upon treatment intensification in high-risk patients. Genomic and clinical data are available as a public resource.

Impaired bone strength estimates at the distal tibia and its determinants in adolescents with anorexia nervosa

BACKGROUND

Altered bone microarchitecture and higher marrow adipose tissue (MAT) may reduce bone strength. High resolution pQCT (HRpQCT) allows assessment of volumetric BMD (vBMD), and size and microarchitecture parameters of bone, while 1H-magnetic resonance spectroscopy (1H-MRS) allows MAT evaluation. We have reported impaired microarchitecture at the non-weight bearing radius in adolescents with anorexia nervosa (AN) and that these changes may precede aBMD deficits. Data are lacking regarding effects of AN on microarchitecture and strength at the weight-bearing tibia in adolescents and young adults, and the impact of changes in microarchitecture and MAT on strength estimates.

OBJECTIVE

To compare strength estimates at the distal tibia in adolescents/young adults with AN and controls in relation to vBMD, bone size and microarchitecture, and spine MAT.

DESIGN AND METHODS

This was a cross-sectional study of 47 adolescents/young adults with AN and 55 controls 14-24years old that assessed aBMD and body composition using DXA, and distal tibia vBMD, size, microarchitecture and strength estimates using HRpQCT, extended cortical analysis, individual trabecular segmentation, and finite element analysis. Lumbar spine MAT (1H-MRS) was assessed in a subset of 19 AN and 22 controls.

RESULTS

Areal BMD Z-scores were lower in AN than controls. At the tibia, AN had greater cortical porosity, lower total and cortical vBMD, cortical area and thickness, trabecular number, and strength estimates than controls. Within AN, strength estimates were positively associated with lean mass, aBMD, vBMD, bone size and microarchitectural parameters. MAT was higher in AN, and associated inversely with strength estimates.

CONCLUSIONS

Adolescents/young adults with AN have impaired microarchitecture at the weight-bearing tibia and higher spine MAT, associated with reduced bone strength.

Trabecular Bone Morphology Correlates With Skeletal Maturity and Body Composition in Healthy Adolescent Girls

Context

Growth in healthy children is associated with changes in bone density and microarchitecture. Trabecular morphology is an additional important determinant of bone strength, but little is currently known about trabecular morphology in healthy young people.

Objective

To investigate associations of trabecular morphology with increasing maturity and with body composition in healthy girls.

Design

Cross-sectional study.

Setting

Academic research center.

Participants

Eighty-six healthy girls aged 9 to 18 years.

Main Outcome Measures

High-resolution peripheral quantitative computed tomography and individual trabecula segmentation were used to assess volumetric bone density, microarchitecture, and trabecular morphology (plate-like vs rod-like) at the distal radius and tibia.

Results

Plate-like bone volume divided by total volume (pBV/TV) increased statistically significantly at the tibia (R = 0.41, P < 0.001), whereas rod-like BV/TV (rBV/TV) decreased statistically significantly at both the radius and tibia (R = -0.34, P = 0.003 and R = -0.28, P = 0.008, respectively) with increasing bone age. In multivariable models, lean mass positively correlated with pBV/TV and plate number at the radius and with plate thickness at both sites. In contrast, fat mass negatively correlated with plate thickness at the tibia and plate surface at both sites. In addition, fat mass positively correlated with rBV/TV and number at the tibia. pBV/TV at both the distal radius and tibia was positively correlated with spine bone mineral density.

Conclusions

Increasing maturity across late childhood and adolescence is associated with changes in trabecular morphology anticipated to contribute to bone strength. Body composition correlates with trabecular morphology, suggesting that muscle mass and adiposity in youth may contribute to long-term skeletal health.

A real-time Global Warming Index

We propose a simple real-time index of global human-induced warming and assess its robustness to uncertainties in climate forcing and short-term climate fluctuations. This index provides improved scientific context for temperature stabilisation targets and has the potential to decrease the volatility of climate policy. We quantify uncertainties arising from temperature observations, climate radiative forcings, internal variability and the model response. Our index and the associated rate of human-induced warming is compatible with a range of other more sophisticated methods to estimate the human contribution to observed global temperature change.

Hypoparathyroidism

This corrects the article DOI: 10.1038/nrdp.2017.55.

Imaging Findings of Metabolic Bone Disease

Metabolic bone diseases are a diverse group of diseases that result in abnormalities of (a) bone mass, (b) structure mineral homeostasis, (c) bone turnover, or (d) growth. Osteoporosis, the most common metabolic bone disease, results in generalized loss of bone mass and deterioration in the bone microarchitecture. Impaired chondrocyte development and failure to mineralize growth plate cartilage in rickets lead to widened growth plates and frayed metaphyses at sites of greatest growth. Osteomalacia is the result of impaired mineralization of newly formed osteoid, which leads to characteristic Looser zones. Hypophosphatasia is a congenital condition of impaired bone mineralization with wide phenotypic variability. Findings of hyperparathyroidism are the result of bone resorption, most often manifesting as subperiosteal resorption in the hand. Renal osteodystrophy is the collection of skeletal findings observed in patients with chronic renal failure and associated secondary hyperparathyroidism and can include osteopenia, osteosclerosis, and "rugger jersey spine." Hypoparathyroidism is most commonly due to iatrogenic injury, and radiographic findings of hypoparathyroidism reflect an overall increase in bone mass. Thyroid hormone regulates endochondral bone formation; and congenital hypothyroidism, when untreated, leads to delayed bone age and absent, irregular, or fragmented distal femoral and proximal tibial epiphyses. Soft-tissue proliferation of thyroid acropachy is most often observed in the hands and feet. The findings of acromegaly are due to excess growth hormone secretion and therefore proliferation of the bones and soft tissues. Vitamin C deficiency, or scurvy, impairs posttranslational collagen modification, leading to subperiosteal hemorrhage and fractures. ^©RSNA, 2016.

FGF23 Is Not Associated With Age-Related Changes in Phosphate, but Enhances Renal Calcium Reabsorption in Girls

CONTEXT

Fibroblast growth factor (FGF)23 is a critical determinant of phosphate homeostasis. The role of FGF23, however, in regulating physiologic changes in serum phosphate and renal phosphate handling across childhood is not well described. In addition, animal models have suggested a role for FGF23 in regulating renal calcium excretion.

OBJECTIVE

To assess changes in FGF23 concentrations across childhood in relation to changes in mineral ions and hormones of mineral ion homeostasis.

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at a Clinical Research Center at a tertiary care hospital.

PATIENTS OR OTHER PARTICIPANTS

Ninety healthy girls ages 9 to 18 years were recruited from the surrounding community.

MAIN OUTCOME MEASURES

The associations of intact and C-terminal FGF23 concentrations with measures of mineral ion homeostasis were determined by univariable and multivariable linear regression.

RESULTS

Serum phosphate and renal phosphate excretion varied with age, as expected (R = -0.49, P < 0.001 and R = -0.48, P < 0.001, respectively). Neither intact nor C-terminal FGF23 varied with age, and FGF23 was not correlated with serum or urinary phosphate. Intact FGF23 was positively correlated with serum calcium (R = 0.39, P < 0.001) and negatively correlated with urinary calcium/creatinine ratio (R = -0.27, P = 0.011).

CONCLUSIONS

The changes in serum and urinary phosphate handling across childhood do not appear to be determined by alterations in FGF23 concentrations. These data may point to a role for FGF23 in calcium regulation in human physiology.

Growth in patients with type 1 diabetes

PURPOSE OF REVIEW

As the incidence of type 1 diabetes (T1DM) continues to rise, complications including impairment of childhood growth remain a major concern. This review provides an overview of alterations in growth patterns before and after the onset of T1DM.

RECENT FINDINGS

Recent advances in this field include several prospective investigations of height and weight trajectories in children leading up to the development of islet autoimmunity and T1DM as well as evaluations of larger cohorts of T1DM patients to better assess predictors of altered growth. In addition, genetic and metabolic investigations have improved our understanding of the more rare severe growth impairment of Mauriac Syndrome.

SUMMARY

Despite advances in medical care of children with T1DM, growth remains suboptimal in this population and likely reflects ongoing metabolic derangement linked with classic microvascular diabetic complications.

Type 2 diabetes and the skeleton: new insights into sweet bones

Substantial evidence shows that skeletal fragility should be considered among the complications associated with type 2 diabetes. Individuals with type 2 diabetes have increased fracture risk, despite normal bone mineral density (BMD) and high BMI-factors that are generally protective against fractures. The mechanisms underlying skeletal fragility in diabetes are not completely understood, but are multifactorial and likely include effects of obesity, hyperglycaemia, oxidative stress, and accumulation of advanced glycation end products, leading to altered bone metabolism, structure, and strength. Clinicians should be aware that BMD measurements underestimate fracture risk in people with type 2 diabetes, and that new treatments for diabetes, with neutral or positive effects on skeletal health, might play a part in the management of diabetes in those at high risk of fracture. Data for the optimum management of osteoporosis in patients with type 2 diabetes are scarce, but in the absence of evidence to the contrary, physicians should follow guidelines established for postmenopausal osteoporosis.

Altered trabecular bone morphology in adolescent and young adult athletes with menstrual dysfunction

CONTEXT

Young amenorrheic athletes (AA) have lower bone mineral density (BMD) and an increased prevalence of fracture compared with eumenorrheic athletes (EA) and non-athletes. Trabecular morphology is a determinant of skeletal strength and may contribute to fracture risk.

OBJECTIVES

To determine the variation in trabecular morphology among AA, EA, and non-athletes and to determine the association of trabecular morphology with fracture among AA.

DESIGN AND SETTING

A cross-sectional study performed at an academic clinical research center.

PARTICIPANTS

161 girls and young women aged 14-26 years (97 AA, 32 EA, and 32 non-athletes).

MAIN OUTCOME MEASURE

We measured volumetric BMD (vBMD) and skeletal microarchitecture using high-resolution peripheral quantitative computed tomography. We evaluated trabecular morphology (plate-like vs. rod-like), orientation, and connectivity by individual trabecula segmentation.

RESULTS

At the non-weight-bearing distal radius, the groups did not differ for trabecular vBMD. However, plate-like trabecular bone volume fraction (pBV/TV) was lower in AA vs. EA (p=0.03), as were plate number (p=0.03) and connectivity (p=0.03). At the weight-bearing distal tibia, trabecular vBMD was higher in athletes vs. non-athletes (p=0.05 for AA and p=0.009 for EA vs. non-athletes, respectively). pBV/TV was higher in athletes vs. non-athletes (p=0.04 AA and p=0.005 EA vs. non-athletes), as were axially-aligned trabeculae, plate number, and connectivity. Among AA, those with a history of recurrent stress fracture had lower pBV/TV, axially-aligned trabeculae, plate number, plate thickness, and connectivity at the distal radius.

CONCLUSIONS

Trabecular morphology and alignment differ among AA, EA, and non-athletes. These differences may be associated with increased fracture risk.

Insulin secretion and sensitivity in healthy adults with low vitamin D are not affected by high-dose ergocalciferol administration: a randomized controlled trial

BACKGROUND

Epidemiologic data suggest that low serum 25-hydroxyvitamin D [25(OH)D] increases insulin resistance and the risk of type 2 diabetes. Few interventional trials have assessed the effect of vitamin D on insulin metabolism, and published results are discordant.

OBJECTIVE

The goal of this study was to perform a detailed assessment of the effect of ergocalciferol administration on glucose and insulin metabolism in healthy people with low total 25(OH)D(total).

DESIGN

This was a 12-wk, double-blinded, randomized controlled trial. We enrolled 90 healthy volunteers aged 18-45 y with serum 25(OH)D ≤20 ng/mL (by immunoassay) and administered 50,000 IU ergocalciferol/wk or placebo for 12 wk. Primary endpoints were change in first-phase insulin response and insulin sensitivity as measured by intravenous glucose tolerance test. Secondary endpoints included change in homeostasis model assessment of insulin resistance; fasting glucose, insulin, and lipids; body mass index (BMI); and blood pressure.

RESULTS

On-study 25(OH)D(total) was assessed by liquid chromatography-tandem mass spectrometry. In the treated group, 25(OH)D(total) rose from 18 ± 7 to 43 ± 12 ng/mL (P < 0.001) with no change in the placebo group. Despite this increase, at 12 wk, there were no between-group differences in either insulin response or insulin sensitivity; nor were there differences in any measured secondary endpoints. There was no evidence of effect modification by sex, race, glucose tolerance status, baseline 25(OH)D(total), or BMI.

CONCLUSION

In healthy persons with low 25(OH)D(total), ergocalciferol administration for 12 wk normalizes 25(OH)D(total) but does not improve insulin secretion, insulin sensitivity, or other markers of metabolic health.

Polar vortices on Earth and Mars: A comparative study of the climatology and variability from reanalyses

Polar vortices on Mars provide case-studies to aid understanding of geophysical vortex dynamics and may help to resolve long-standing issues regarding polar vortices on Earth. Due to the recent development of the first publicly available Martian reanalysis dataset (MACDA), for the first time we are able to characterise thoroughly the structure and evolution of the Martian polar vortices, and hence perform a systematic comparison with the polar vortices on Earth. The winter atmospheric circulations of the two planets are compared, with a specific focus on the structure and evolution of the polar vortices. The Martian residual meridional overturning circulation is found to be very similar to the stratospheric residual circulation on Earth during winter. While on Earth this residual circulation is very different from the Eulerian circulation, on Mars it is found to be very similar. Unlike on Earth, it is found that the Martian polar vortices are annular, and that the Northern Hemisphere vortex is far stronger than its southern counterpart. While winter hemisphere differences in vortex strength are also reported on Earth, the contrast is not as large. Distinctions between the two planets are also apparent in terms of the climatological vertical structure of the vortices, in that the Martian polar vortices are observed to decrease in size at higher altitudes, whereas on Earth the opposite is observed. Finally, it is found that the Martian vortices are less variable through the winter than on Earth, especially in terms of the vortex geometry. During one particular major regional dust storm on Mars (Martian year 26), an equatorward displacement of the vortex is observed, sharing some qualitative characteristics of sudden stratospheric warmings on Earth.

Prevalence and predictors of vitamin D deficiency in healthy adults

OBJECTIVE

Vitamin D deficiency is highly prevalent in high-risk patient populations, but the prevalence among otherwise healthy adults is less well-defined. The goal of this study was to determine the prevalence and predictors of low 25-hydroxyvitamin D [25(OH)D] levels in healthy younger adults.

METHODS

This was a cross-sectional study of 634 healthy volunteers aged 18-50 years performed between January, 2006 and May, 2008. We measured serum 25(OH)D and parathyroid hormone and recorded demographic variables including age, sex, race, and use of multivitamin supplements.

RESULTS

Thirty-nine percent of subjects had 25(OH)D ≤ 20 ng/mL and 64% had 25(OH)D ≤ 30 ng/mL. Predictors of lower 25(OH)D levels included male sex, black or Asian race, and lack of multivitamin use (P<0.001 for each predictor). Seasonal variation in 25(OH)D levels was present in the overall cohort but was not observed in multivitamin users. Lower 25(OH)D levels were associated with increased risk of elevated parathyroid hormone. Regression models predicted 25(OH)D levels ≤ 20 or ≤ 30 ng/mL with areas under the receiver operating characteristic curves of 0.76 and 0.80, respectively.

CONCLUSION

Low 25(OH)D levels are prevalent in healthy adults and may confer risk of skeletal disease. Black and Asian adults are at increased risk of deficiency and multivitamin use appears partially protective. Our models predicting low 25(OH)D levels may guide decision-making regarding whom to screen for vitamin D deficiency.

Long-term follow-up of patients with hypoparathyroidism

CONTEXT

Despite tremendous interest in hypoparathyroidism, large cohort studies describing typical treatment patterns, laboratory parameters, and rates of complications are lacking.

OBJECTIVE

Our objective was to characterize the course of disease in a large cohort of hypoparathyroid patients.

DESIGN AND SETTING

We conducted a chart review of patients with permanent hypoparathyroidism identified via a clinical patient data registry. Patients were seen at a Boston tertiary-care hospital system between 1988 and 2009.

PATIENTS

We identified 120 patients. Diagnosis was confirmed by documented hypocalcemia with a simultaneous low or inappropriately normal PTH level for at least 1 yr. Mean age at the end of the observation period was 52 ± 19 (range 2-87) yr, and the cohort was 73% female.

MAIN OUTCOME MEASURE

We evaluated serum and urine laboratory results and renal and brain imaging.

RESULTS

We calculated time-weighted average serum calcium measurements for all patients. The time-weighted average for calcium was between 7.5 and 9.5 mg/dl for the majority (88%) of patients. Using linear interpolation, we estimated the proportion of time within the target calcium range for each patient with a median of 86% (interquartile range 67-98%). Of those with a 24-h urine collection for calcium (n = 53), 38% had at least one measurement over 300 mg/d. Of those with renal imaging (n = 54), 31% had renal calcifications, and 52% of those with head imaging (n = 31) had basal ganglia calcifications. Rates of chronic kidney disease stage 3 or higher were 2- to 17-fold greater than age-appropriate norms.

CONCLUSIONS

Hypoparathyroidism and its treatment carry a large burden of disease. Renal abnormalities are particularly common.

Assessing the daily consistency of bladder filling using an ultrasonic Bladderscan device in men receiving radical conformal radiotherapy for prostate cancer

OBJECTIVE

Consistency in target organ and organ at risk position from planning to treatment is an important basic principle of radiotherapy. This study evaluates the effectiveness of bladder-filling instructions in achieving a consistent and reproducible bladder volume at the time of planning CT and daily during the course of radical radiotherapy for prostate cancer. It also assessed the rate of bladder filling before and at the end of radiotherapy.

METHODS

30 men attending for radiation therapy planning for prostate cancer received written and verbal bladder-filling instructions. They had their bladder volume assessed using a bladder ultrasound scanner post-void, immediately prior to planning CT scan and then daily immediately prior to treatment while in the therapy position. The inflow was calculated using the void and full bladder volumes and the time for the bladder to fill.

RESULTS

The mean bladder volume at the time of planning was 282 ml (range 89-608 ml, standard deviation (SD) = 144.5 ml). This fell during treatment, with a mean value for all treatments of 189 ml (range 11-781 ml, SD = 134 ml). During radiotherapy, 76% (828/1090), 53% (579/1090) and 36% (393/1090) of bladder volumes had >50 ml, >100 ml and >150 ml difference, respectively when compared with their volume at the time of planning. Inflow reduced from 4.6 ml min(-1), SD = 2.9 min(-1) at planning to 2.5 min(-1), SD = 1.8 min(-1) after radiotherapy.

CONCLUSION

The Bladderscan device (BVI 6400 Bladderscan, Verathon Medical UK, Sandford, UK) provides an effective means of assessing bladder volume prior to radiotherapy for prostate cancer. The evaluated bladder-filling protocol does not produce consistent, reproducible bladder volumes for radiotherapy.

SENSORY NEURON DEGENERATION IN VITAMIN DEFICIENCY : DEGENERATION OF THE POSTERIOR COLUMNS OF THE SPINAL CORD, PERIPHERAL NERVES, AND DORSAL ROOT GANGLION CELLS IN YOUNG PIGS FED A DIET CONTAINING THIAMIN (B(1)) AND RIBOFLAVIN BUT OTHERWISE DEFICIENT IN VITAMIN B COMPLEX

Young pigs were given an artificial diet presumably adequate in all respects. As they developed, the quantity of yeast was gradually reduced while thiamin (vitamin B₁) and riboflavin were given in its place. The rate of growth decreased, the general condition of the animals became impaired, and marked ataxia without motor weakness developed. Histologically, severe degeneration of the posterior columns of the spinal cord, the dorsal root ganglion cells, and the peripheral nerves was found.

Regulation of calcium homeostasis and bone metabolism in the fetus and neonate

PURPOSE OF REVIEW

Regulation of calcium and phosphorus levels in the fetus and neonate is critical for proper bone development and mineralization.

RECENT FINDINGS

Parathyroid hormone-related peptide plays an important role in transferring calcium across the placenta into the fetal circulation. In contrast, the factors controlling placental phosphate transport have not yet been explored, and numerous studies have indicated that maternal and childhood vitamin D deficiency continues to be a significant clinical concern.

SUMMARY

The molecular basis for mineral ion homeostasis in the fetus and child remains incompletely understood. More attention must be paid to identifying and treating maternal, neonatal, and childhood vitamin D deficiency.

Radioactive iodine for hyperthyroidism in children and adolescents: referral rate and response to treatment

OBJECTIVES

Radioactive iodine ((131)I) therapy is increasingly viewed as a safe and effective treatment for paediatric and adolescent hyperthyroidism. Our objective was to estimate treatment response and its predictors and describe current referral practices for (131)I therapy.

DESIGN

Retrospective study.

PATIENTS

One hundred and thirty-one children 30 days-21 years old with laboratory evidence of hyperthyroidism, seen in an academic paediatric and adolescent endocrinology practice.

MEASUREMENTS

Rate of referral, indications for (131)I, predictors of poor treatment response.

RESULTS

Thirty-eight of 102 patients with persistent hyperthyroidism (37%) received (131)I (160 μCi/g thyroid tissue/(131)I uptake), as did an additional 10 patients initially evaluated by adult thyroidologists. Primary indications were intolerance to (29%) or poor control on (19%) antithyroid drugs, patient preference (50%) and unknown (2%). Of 48 patients treated with (131)I, 89% and 11% became hypothyroid after one and two (131)I doses, respectively. The goal of (131)I therapy was attainment of hypothyroidism. 'Poor treatment response' (seen in 27%) was defined as requirement for a second (131)I dose or failure to achieve hypothyroidism after 6 months. Predictors of poor treatment response included: previous use of antithyroid drugs (37%vs. 0%, P = 0.02), ophthalmopathy (58%vs. 8%, P = 0.002), and an interval of ≥ 12 months from diagnosis to (131)I (50%vs. 10%, P = 0.003). A very elevated free T4 tended to be more prevalent in those with poor response.

CONCLUSIONS

In children and adolescents with hyperthyroidism, high rates of success after (131)I are achievable. Use of antithyroid drugs, pre-existing eye disease and prolonged time to (131)I may confer relative resistance to (131)I.

Recto-urethral fistula following brachytherapy for localized prostate cancer

OBJECTIVE

The use of prostate brachytherapy (BT) in the management of prostate cancer is increasing. BT is often chosen because of its perceived lower toxicity when compared with other radical therapy options. Rarely however serious complications can occur. One such complication is recto-urethral fistula (RUF). We report the incidence of RUF following BT at our centre and review the potential factors in fistula development.

METHOD

A prospectively collected database was used to identify cases of RUF among 1455 patients treated with prostate BT at a single UK centre with at least 2 years of follow up. This included patients treated with BT monotherapy, as well as those treated with BT combined with external beam radiotherapy and BT used as salvage as all these groups have a higher incidence of RUF. Implant dose and volume characteristics for those patients, their co-morbidities and history of endoscopic procedures were recorded.

RESULTS

Recto-urethral fistula was identified in three (0.2%) patients, occurring at 19-27 months following BT. All these patients had BT monotherapy. All three patients had rectal symptoms after their BT and had been investigated with endoscopy and low rectal biopsy. Subsequent surgical management with faecal and/or urinary diversion was required. On review of patients' BT details, radiation dose and volume parameters were higher on the postprocedure CT calculations than had been suggested by the preimplant plan. No other predisposing risk factors for RUF were identified.

CONCLUSION

The incidence of RUF in our population is low. RUF following BT has been associated with rectal biopsy in previous series and this is confirmed in our report. Gastrointestinal specialists should not perform biopsy of the anterior rectum in patients who have had BT unless there is a very high clinical suspicion of malignancy.

Interhospital provision of emergency vascular services for a large population: early outcomes and clinical results

Background

In 1999 an emergency vascular service for Bristol and Avon (including Weston-Super-Mare) (population approximately 1 million) was initiated.

Methods

Collaboration between Bristol Royal Infirmary, Frenchay and Southmead Hospitals provides week-on–week-off vascular cover for patients requiring urgent and emergency interventions within 24 h. The rota accommodates National Confidential Enquiry into Perioperative Deaths and Vascular Surgical Society of Great Britain and Ireland recommendations, governance issues, and enhances emergency vascular care for Avon residents. Prospectively collected data for the first year (May 1999 to April 2000) are reviewed.

Results

There were 289 emergency admissions. (In-hospital referrals were not transferred but contributed up to 40 per cent of the extra emergency workload per unit.) Referrals were also accepted from seven Trusts outside the designated catchment area. Caseload included 86 patients with a ruptured or acutely symptomatic aortic aneurysm, of whom 69 underwent operation (30 per cent mortality rate); 17 patients were not operated on. Some 136 patients had critical leg ischaemia (43 acute, 93 chronic); angiography or duplex ultrasonography was performed in 105 cases (77 per cent); 39 patients (29 per cent) had undergone previous intervention for peripheral vascular disease; the mortality rate was 18 (13 per cent) of 136; 18 (13 per cent) of 136 patients required an amputation. Other cases included: upper limb ischaemia, 20 (7 per cent); paediatric emergency, seven (2 per cent); symptomatic carotid disease, five (2 per cent; four endarterectomies with no death or stroke). Some 5 per cent of referrals were inappropriate (venous ulcer, spinal stenosis, etc.). No outcomes were compromised by interhospital transfers. Vascular surgeons operated on nine high-risk patients away from their ‘base’ hospital. A consultant was the principal or assistant operator in more than 95 per cent of operations but, despite trainee rota adjustments, a designated vascular trainee was present in only about 40 per cent of cases.

Conclusion

Interhospital provision of emergency vascular services for a large population is feasible, does not compromise quality of care, and regulates emergency workload. Further attention to training issues is indicated.

Genetic polymorphism of MUC7: allele frequencies and association with asthma

MUC7 encodes a small salivary mucin, previously called MG2, a glycoprotein with a putative role in facilitating the clearance of oral bacteria. The central domain of this glycoprotein was previously shown to comprise five or six tandemly repeated units of 23 amino-acids which carry most of the O-linked glycans. The polymorphism of these two allelic forms (MUC7*5 or MUC7*6) has been confirmed in this study in which we have analysed a large cohort of subjects (n = 375) of various ethnic origins. We have also identified a novel rare allele with eight tandem repeats (MUC7*8). MUC7*6 was the most common allele (0.78-0.95) in all the populations tested. The tandem repeat arrays of 22 MUC7*5 alleles and 34 MUC7*6 alleles were sequenced. No sequence differences were detected in any of the MUC7*6 alleles. Twenty-one MUC7*5 alleles sequenced lacked the 4th tandem repeat (structure TR12356), while one showed the structure TR12127. The structure of the MUC7*8 allele was TR12343456. Because of the known role of MUC7 in bacterial binding, and thus its potential involvement in susceptibility to chest disease we also tested MUC7 in our previously described series of Northern European atopic individuals with and without associated asthma. The MUC7*5 allele was rarer in the atopic asthmatics than in the atopic non-asthmatics (P = 0.014, OR for no asthma in atopic individuals 3.13, CI 1.01-6.10), and the difference in frequency between all asthmatics and all non-asthmatics was statistically significant (P = 0.009) while there was no difference between atopy and non-atopy (P = 0.199). In this study we also report the electrophoretic analysis of the MUC7 glycoprotein in saliva from individuals of different MUC7 genotype.

Nucleosome remodeling at the IL-12 p40 promoter is a TLR-dependent, Rel-independent event

Lipopolysaccharide (LPS) induction of the gene encoding interleukin 12 p40 requires remodeling of a promoter-encompassing nucleosome and the Toll-like receptor (TLR)-mediated activation of a c-Rel-containing complex. Analysis of TLR4-mutant mice revealed that remodeling requires TLR signaling. However, Rel proteins and other proteins required for transcription of an integrated p40 promoter were insufficient for remodeling. c-Rel was also unnecessary for remodeling, as remodeling was observed in c-Rel-/- macrophages, which lack p40 transcripts. These results suggest that remodeling requires TLR signaling pathways that diverge from the c-Rel activation pathways. The factors that stimulate remodeling may represent, therefore, newly identified targets of TLR signaling and of agents that regulate inflammatory responses and TH1 development.

Polymorphism of human mucin genes in chest disease: possible significance of MUC2

Most of the genes that encode epithelial mucins are highly polymorphic due to variations in the length of domains of tandemly repeated (TR) coding sequence, the part of the apomucin that is heavily glycosylated. We report here for the first time a difference in the distribution of MUC TR length alleles in chest disease. We examined the distribution of the length alleles of those MUC genes whose expression we have confirmed in the bronchial tree in an age- and sex-matched series of 50 pairs of atopic patients with and without asthma. There was no significant difference in the distribution of alleles of MUC1, MUC4, MUC5AC, and MUC5B. MUC2, however, showed a highly significant difference in distribution. The atopic, nonasthmatic individuals showed an allele distribution that was very different from all our other patient and control groups, this group showing a longer mean allele length. The observations suggest that longer MUC2 alleles may help protect atopic individuals from developing asthma, though the effect may be due to a linked gene. The biological significance of this variation with respect to susceptibility to asthma will merit further investigation, and it will also be important to substantiate this finding on an independent data set.

Follicular lymphoma can be distinguished from benign follicular hyperplasia by flow cytometry using simultaneous staining of cytoplasmic bcl-2 and cell surface CD20

The distinction between benign follicular hyperplasia (FH) and follicular lymphoma (FL) is sometimes problematic. We wanted to determine whether the expression of bcl-2 of FH was quantitatively different from that of FL, using surface CD20 expression as a discriminator of the various lymphoid compartments. Lymph node cell suspensions from 12 cases of FH and 17 cases of FL were analyzed by flow cytometry using a combined surface CD20 and intracellular bcl-2 staining. CD20- T cells in FH demonstrated the same bcl-2 expression as the CD20+ mantle cells, but the bright CD20+ germinal center cells showed near absence of bcl-2 expression. In contrast, the neoplastic cells of FL showed greater bcl-2 expression than the T cells of the same tumors and all cell populations of FH. This difference was particularly significant between the neoplastic B cells of FL and the germinal center cells of FH. The combined analysis of CD20 and bcl-2 should be useful for the differential diagnosis between FH and FL and particularly applicable to limited samples or when B-cell clonality is in question. Whether the quantitation of bcl-2 expression can be of further discriminatory value in malignant lymphomas remains to be determined.

HIV and tuberculosis co-infection in an inner London hospital--a prospective anonymized seroprevalence study

OBJECTIVES

Since 1987 there has been an increase in tuberculosis notifications in the U.K., with this increase disproportionately affecting London. A recent national survey suggests that co-infection with HIV occurs in less than 5% of tuberculosis patients. This study asked if local co-infection rates in Inner London differed from the national results.

METHODS

157 consecutive patients starting antituberculous chemotherapy were venesected 2 weeks into treatment. Anonymized blood samples were screened for antibodies for HIV-1 and HIV-2 by enzyme-linked immunosorbent assay (ELISA). Epidemiological data were collected on each patient which was also coded before HIV test results were known.

RESULTS

Of 157 patients commencing antituberculous therapy, 39 patients (24.8%) were found to be co-infected with HIV-1. HIV-negative and positive patients were similar in terms of age and sex. When 98 patients giving their country of origin as other than Europe were considered there were 22 co-infected with HIV (22.4%). Of the 39 HIV-positive identified in this study, 37 were also identified by our voluntary HIV testing programme.

CONCLUSIONS

This study has shown that there may be very different rates of co-infection at a local level in the U.K. The local variation may be missed by national surveys and diverse local testing procedures. Anonymous testing identified only two patients with tuberculosis and HIV infection who were not identified by our voluntary HIV testing programme and this suggests that offering HIV tests to patients with tuberculosis is largely taken up by those at risk of HIV infection. Surveillance studies of this type are important in identifying marked local variation from the national pattern of HIV and Mycobacterium tuberculosis infection.

Apoprotein B100 has a prolonged interaction with the translocon during which its lipidation and translocation change from dependence on the microsomal triglyceride transfer protein to independence

When lipid synthesis is limited in HepG2 cells, apoprotein B100 (apoB100) is not secreted but rapidly degraded by the ubiquitin-proteasome pathway. To investigate apoB100 biosynthesis and secretion further, the physical and functional states of apoB100 destined for either degradation or lipoprotein assembly were studied under conditions in which lipid synthesis, proteasomal activity, and microsomal triglyceride transfer protein (MTP) lipid-transfer activity were varied. Cells were pretreated with a proteasomal inhibitor (which remained with the cells throughout the experiment) and radiolabeled for 15 min. During the chase period, labeled apoB100 remained associated with the microsomes. Furthermore, by crosslinking sec61beta to apoB100, we showed that apoB100 remained close to the translocon at the same time apoB100-ubiquitin conjugates could be detected. When lipid synthesis and lipoprotein assembly/secretion were stimulated by adding oleic acid (OA) to the chase medium, apoB100 was deubiquitinated, and its interaction with sec61beta was disrupted, signifying completion of translocation concomitant with the formation of lipoprotein particles. MTP participates in apoB100 translocation and lipoprotein assembly. In the presence of OA, when MTP lipid-transfer activity was inhibited at the end of pulse labeling, apoB100 secretion was abolished. In contrast, when the labeled apoB100 was allowed to accumulate in the cell for 60 min before adding OA and the inhibitor, apoB100 lipidation and secretion were no longer impaired. Overall, the data imply that during most of its association with the endoplasmic reticulum, apoB100 is close to or within the translocon and is accessible to both the ubiquitin-proteasome and lipoprotein-assembly pathways. Furthermore, MTP lipid-transfer activity seems to be necessary only for early translocation and lipidation events.