Immobilization Hypercalcemia (IH) in an Adult After Spinal Cord Injury

Background: Immobilization hypercalcemia (IH) is an uncommon diagnosis and little has been published about management of this condition. We present a case of IH and discuss clinical aspects of this unique bone metabolism state. Case: 32-year-old female with history significant for IV drug use, presented to the hospital with features of septic shock, Work up showed MRSA bacteremia associated with tricuspid endocarditis and septic pulmonary emboli. MRI of the spine done for progressive weakness of extremities revealed a cervical epidural abscess leading to spinal cord compression and myelomalacia. She underwent spinal abscess drainage and corpectomy, remained quadriplegic. 8 weeks later we were consulted to see her at inpatient rehabilitation facility for hypercalcemia. Labs showed Creat(0.6 mg/dl), hypercalcemia with corrected Calcium of 12.9 mg/dl f. Further workup showed suppressed PTH (< 6), V D-25 at (< 10 mg/dl). Phosphate (normal). ACE levels, PTHrp, Vit. D 1,25, SPEP, UPEP,and TSH were all normal. 24 hours urine calcium showed hypercalciuria, 400 mg/ml. Fasting Bone markers were elevated with serum N-telopeptide > 40 nM BCE, ref range (6.2–19.0) and C-Telopeptide is 2060 pg/ml ref range (60–650), which indicates increase bone turnover. IH was diagnosed and hydration attempted for few weeks. Serum calcium remained at 13 mg/dl, so she received a single slow infusion of pamidronate 30 mg. 4 days after infusion, calcium levels decreased to normal value of 10.2 mg/dl without any side effects. She remained normocalcemic 5 weeks post infusion. Discussion: IH is an uncommon condition but early recognition and intervention will minimize secondary long-term complications such as kidney stones, Osteoporosis or low bone mass, renal failure and acute pancreatitis. Albert, Fuller described IH in 1941(1). Most cases of IH had been reported in children and adolescents with high bone turn over following recent spinal cord injury(2–3). Very few reports have been published in young adults such as our patient,IH is attributed to prolonged immobilization from paralysis due to spinal cord injury,and other etiology (2–4), Proposed mechanism includes decreased mechanical stress on the bone which leads to increase bone resorption and remodeling and demineralization. To establish the diagnoses of IH, an exhaustive evaluation is warranted to rule out other causes of PTH dependent and independent hypercalcemia(5). Multiple treatment approaches have been used over the past few decades including early mobilization, hydration., saline diuresis, subcutaneous Calcitonin, glucocorticoids (6), IV sodium sulphate and phosphate (7). Bisphosphonates are the preferred pharmacological treatment of IH. Nonnitrogen containing bisphosphonates including clodronate and etidronate (8–9),. are not preferred due to concern for bone demineralization and osteomalacia. (10). Pamidronate has been used to treat IH due to its efficacy, safely and cost (11). Caution to be exercised in those patients with kidney disease.

SUN-392 Bone Mineral Density and Body Mass Index in Men with Cystic Fibrosis

Osteoporosis is an important endocrine complication of cystic fibrosis (CF). Low bone mass in CF patients has multiple contributing causes including vitamin D deficiency, calcium malabsorption, pulmonary infection and cytokine production, malnutrition, a sedentary life style, cumulative steroid dose, delayed puberty, and hypogonadism. The objective of this study was to examine the relationship between BMI and bone density of the hip and spine in adult men with CF. We conducted a retrospective chart review of adult men with CF receiving care at an academic medical center. Medical records of 43 men ages 19-60 (32.1±9.8) years were reviewed. 8 men with lung transplant, or receiving chronic glucocorticoid or androgen treatment were excluded. One subject was excluded as his BMI was >3SD above the mean. BMD was measured by dual-energy x-ray absorptiometry at the lumbar spine (LS) and hip. The mean ± SD BMI of the study population was 24.10 ± 5.24 kg/m2, mean LS BMD was 0.96 ± 0.204 g/cm2 and mean hip BMD was 0.701 ± 0.382 g/cm2. Men were divided into three groups: normal BMD, osteopenia, or osteoporosis, based on current guidelines. 8 (24%) men were found to have normal bone density (Z=0.40±0.60), 19 (56%) had osteopenia (Z= -1.57±0.67) and 7 (20%) had osteoporosis (Z= -3.27±0.83). Of these 7, 6 had osteoporosis of the LS only, and one patient had osteoporosis of the hip; 5 were being treated with a bisphosphonate. The three groups of men were similar in age (P=0.93). 25OH-vitamin D levels were 22.6±4.4, 35.6±12.7 and 27.0±13.4 ng/mL, respectively (p=0.03). There was a significant (p=0.023) difference in BMI among these three groups (26.33±4.80 vs 23.25 ± 3.01 vs 20.96±3.64 kg/m2). BMI was strongly positively correlated with LS BMD (r = 0.54, P<0.001) but not with BMD of the hip (r = 0.11, p=0.55). Moreover, LS BMD was highly predicted by body weight (r = 0.90, P<0.0001) but not significantly by height (r = 0.26, p=0.16). These findings indicate that CF-related bone disease (CF-RBD) affecting the LS is common in adult men, and that body weight is a major determinant of LS BMD in men with CF. Possible mechanisms for this association include signaling pathways related to nutritional status and sex steroids.

Association Between Residential Greenness and Cardiovascular Disease Risk

Background Exposure to green vegetation has been linked to positive health, but the pathophysiological processes affected by exposure to vegetation remain unclear. To study the relationship between greenness and cardiovascular disease, we examined the association between residential greenness and biomarkers of cardiovascular injury and disease risk in susceptible individuals. Methods and Results In this cross-sectional study of 408 individuals recruited from a preventive cardiology clinic, we measured biomarkers of cardiovascular injury and risk in participant blood and urine. We estimated greenness from satellite-derived normalized difference vegetation index ( NDVI ) in zones with radii of 250 m and 1 km surrounding the participants' residences. We used generalized estimating equations to examine associations between greenness and cardiovascular disease biomarkers. We adjusted for residential clustering, demographic, clinical, and environmental variables. In fully adjusted models, contemporaneous NDVI within 250 m of participant residence was inversely associated with urinary levels of epinephrine (-6.9%; 95% confidence interval, -11.5, -2.0/0.1 NDVI ) and F2-isoprostane (-9.0%; 95% confidence interval, -15.1, -2.5/0.1 NDVI ). We found stronger associations between NDVI and urinary epinephrine in women, those not on β-blockers, and those who had not previously experienced a myocardial infarction. Of the 15 subtypes of circulating angiogenic cells examined, 11 were inversely associated (8.0-15.6% decrease/0.1 NDVI ), whereas 2 were positively associated (37.6-45.8% increase/0.1 NDVI ) with contemporaneous NDVI . Conclusions Independent of age, sex, race, smoking status, neighborhood deprivation, statin use, and roadway exposure, residential greenness is associated with lower levels of sympathetic activation, reduced oxidative stress, and higher angiogenic capacity.

Circulating angiogenic stem cells in type 2 diabetes are associated with glycemic control and endothelial dysfunction

Circulating angiogenic cells (CACs) of various described phenotypes participate in the regeneration of the damaged endothelium, but the abundance of these cells is highly influenced by external cues including diabetes. It is not entirely clear which CAC populations are most reflective of endothelial function nor which are impacted by diabetes. To answer these questions, we enrolled a human cohort with variable CVD risk and determined relationships between stratified levels of CACs and indices of diabetes and vascular function. We also determined associations between CAC functional markers and diabetes and identified pro-angiogenic molecules which are impacted by diabetes. We found that subjects with low levels of CD34+/AC133+/CD31+/CD45dim cells (CAC-3) had a significantly higher incidence of diabetes (p = 0.004), higher HbA1c levels (p = 0.049) and higher CVD risk scores. Furthermore, there was an association between low CAC-3 levels and impaired vascular function (p = 0.023). These cells from diabetics had reduced levels of CXCR4 and VEGFR2, while diabetics had higher levels of certain cytokines and pro-angiogenic molecules. These results suggest that quantitative and functional defects of CD34+/AC133+/CD31+/CD45dim cells are associated with diabetes and vascular impairment and that this cell type may be a prognostic indicator of CVD and vascular dysfunction.

Residential Proximity to Major Roadways Is Associated With Increased Levels of AC133+ Circulating Angiogenic Cells

OBJECTIVES

Previous studies have shown that residential proximity to a roadway is associated with increased cardiovascular disease risk. Yet, the nature of this association remains unclear, and its effect on individual cardiovascular disease risk factors has not been assessed. The objective of this study was to determine whether residential proximity to roadways influences systemic inflammation and the levels of circulating angiogenic cells.

APPROACH AND RESULTS

In a cross-sectional study, cardiovascular disease risk factors, blood levels of C-reactive protein, and 15 antigenically defined circulating angiogenic cell populations were measured in participants (n=316) with moderate-to-high cardiovascular disease risk. Attributes of roadways surrounding residential locations were assessed using geographic information systems. Associations between road proximity and cardiovascular indices were analyzed using generalized linear models. Close proximity (<50 m) to a major roadway was associated with lower income and higher rates of smoking but not C-reactive protein levels. After adjustment for potential confounders, the levels of circulating angiogenic cells in peripheral blood were significantly elevated in people living in close proximity to a major roadway (CD31(+)/AC133(+), AC133(+), CD34(+)/AC133(+), and CD34(+)/45(dim)/AC133(+) cells) and positively associated with road segment distance (CD31(+)/AC133(+), AC133(+), and CD34(+)/AC133(+) cells), traffic intensity (CD31(+)/AC133(+) and AC133(+) cells), and distance-weighted traffic intensity (CD31(+)/34(+)/45(+)/AC133(+) cells).

CONCLUSIONS

Living close to a major roadway is associated with elevated levels of circulating cells positive for the early stem marker AC133(+). This may reflect an increased need for vascular repair. Levels of these cells in peripheral blood may be a sensitive index of cardiovascular injury because of residential proximity to roadways.

Sex hormone-binding globulin and the risk for metabolic syndrome in children of South Asian Indian origin

OBJECTIVE

To determine whether the plasma level of sex hormone-binding globulin (SHBG) identifies South Asian Indian children at risk for metabolic syndrome.

METHODS

Adults and their children aged 5 to 9 years were recruited at the annual health fair at the Hindu temple serving the South Asian Indian community in Louisville, Kentucky. Anthropometric data were collected in adults and children, and blood pressure, lipid, and glucose levels were measured in adults. SHBG levels were measured in children using a fingerstick blood sample. In adults, metabolic syndrome was diagnosed according to the International Diabetes Federation criteria. Twelve months later, follow-up anthropometric data were obtained for a portion of the children.

RESULTS

The study included 30 sets of parents and 30 children. The prevalence of metabolic syndrome among 310 adults attending the health fair was 42% in men and 39% in women. Children with 1 parent with metabolic syndrome had 24% lower SHBG levels that increased to 55% if both parents had metabolic syndrome. SHBG levels were inversely related to waist circumference and to body mass index percentile. Both SHBG and waist circumference predicted weight gain over 1 year in children. CONCLUSIONS Low SHBG levels were found in South Asian Indian children whose parents had attributes of metabolic syndrome. The dose dependency of SHBG is consistent with inheritance of a genetic trait, and if the results are applicable to other racial/ethnic groups, SHBG may be a useful marker to identify at-risk children for early intervention.