Increased Calcium Intake Does Not Suppress Circulating 1,25-Dihydroxyvitamin D in Normocalcemic Patients with Sarcoidosis

Ca absorption is regulated by 1,25(OH)2D, and serum values vary inversely with Ca intake. In sarcoidosis, 1,25(OH)2D is produced by alveolar macrophages in response to y-interferon, and patients may develop hypercalcemia after prolonged exposure to sunlight and increased dermal production of vitamin D3. To determine if increased Ca intake suppresses serum 1,25(OH)2D in normocalcemic patients and to identify those at risk, 17 normal subjects and 11 patients were studied on a metabolic ward for two and one-half days while receiving first 400 and then 1,000 mg/d of Ca. On the low Ca intake, serum angiotensin-converting enzyme (ACE), an index of disease activity, was higher in only three of the patients than in the controls, mean serum 1,25(OH)2D was higher in the patients, and mean serum total Ca, serum Ca , and urinary Ca were not different in the two groups. On the higher Ca intake, mean urinary Ca increased in both groups, but mean serum 1,25(OH)2D was suppressed only in the normal subjects. Thus, 1,25(OH)2D production is abnormally regulated, indicating that (a) normocalcemic patients with sarcoidosis are at risk for developing abnormal Ca metabolism, and (b) a better index of disease activity is provided by the oral Ca suppression test than by serum ACE. (J. Clin. Invest. 1993. 91:1396- 1398.

Association between bone mineral density and incidence of breast cancer.

INTRODUCTION: Previous studies have suggested an inverse relationship between bone mineral density (BMD) and breast cancer incidence. The primary objective of this study was to assess whether BMD is associated with risk of subsequent breast cancer occurrence in the female population of southern Israel. METHODS: The electronic medical charts of women who underwent BMD at the Soroka Medical Center (SMC) between February 2003 and March 2011 were screened for subsequent breast cancer diagnoses. Women were divided by tertiles of BMD at 3 skeletal sites: lumbar spine (LS, L1-4), total hip (TH) and femoral neck (FN). The incidence of breast cancer was calculated. RESULTS: Of 15268 women who underwent BMD testing, 86 were subsequently diagnosed with breast cancer. Most women in the study were older than 50 years (94.2% and 92.7%, respectively; p = 0.597). Women who subsequently developed breast cancer had a higher mean body-mass index (BMI) (30.9 ± 5.5 vs. 29.1 ± 5.7 p = 0.004) and the mean BMD Z-score was significantly higher than in those without breast cancer for all 3 skeletal sites (LS: 0.36 ± 1.58 vs. -0.12 ± 1.42, p = 0.002; TH: 0.37 ± 1.08 vs. 0.03 ± 1.02, p = 0.002; FN: 0.04 ± 0.99 vs. -0.18 ± 0.94; p = 0.026). Women in the highest Z-score tertiles at the FN and TH had a higher chance of developing breast cancer compared to the lowest tertile; odds ratio of 2.15, 2.02, respectively (P = 0.004 and 0.01 respectively). No association was found between the BMD Z-score and the stage, histology, grade or survival from breast cancer. CONCLUSIONS: This study provides additional support for an inverse association between BMD and the risk of breast cancer

Tested population characteristics at the time of BMD measurement. Age, BMI25(OH)D and PTH are presented as mean ± SD.

*<p>Data was available fort 40% of the women.</p>**<p>Data was available for 15% of the women.</p

Hazard ratio for acquiring breast cancer diagnosis according to BMD Z-score tertiles.

<p>The lowest Z- score tertile was used as reference (HR = 1).</p><p>Multivariate analysis (Cox regression) adjusted for age and BMI.</p

Time to diagnosis of breast cancer following BMD measurement in tertiles of BMD Z score at three skeletal sites.

<p>A. Femoral neck, B. Total hip, C. Lumbar spine.</p

Breast cancer characteristics according to femur neck BMD Z score tertiles (N = 86).

<p>This paper was presented in part at the annual meeting of the Endocrine Society, Houston Texas USA Jun 2012.</p

Flow chart of the study population selection.

<p>Flow chart of the study population selection.</p