Acute and chronic effects of hypercalcaemia on cortical excitability as studied by 5 Hz repetitive transcranial magnetic stimulation.

We designed the present study to disclose changes in cortical excitability in humans with hypercalcaemia, by delivering repetitive transcranial magnetic stimulation (rTMS) over the primary motor area (M1). In 22 patients with chronic hypercalcaemia related to primary hyperparathyroidism and 22 age-matched healthy subjects 5 Hz-rTMS was delivered at rest and during a sustained voluntary contraction of the target muscle. Changes in the resting motor threshold (RMT), motor evoked potential (MEP) amplitudes and cortical silent period (CSP) duration were measured and compared in patients and healthy controls. Two of the 22 patients were re-tested after parathyroidectomy when serum calcium had normalized. In a subgroup of healthy subjects, changes in the rTMS parameters were tested before and after acute hypercalcaemia. No significant difference between healthy normocalcaemic subjects and chronic hypercalcaemic patients was found in the RMT values and MEP amplitude and CSP duration evoked by the first stimulus of the trains. During the course of 5 Hz-rTMS trains, MEP size increased significantly less in patients with chronic hypercalcaemia than in healthy subjects, whereas the CSP duration lengthened to a similar extent in both groups. In the two patients studied after parathyroidectomy, rTMS elicited a normal MEP amplitude facilitation. Our findings indicate that acute hypercalcaemia significantly decreased the MEP amplitude facilitation. Given that 5 Hz-rTMS modulates cortical excitability through mechanisms resembling short-term synaptic enhancement, the reduction of MEP amplitude facilitation by hypercalcaemia may be related to Ca2+-dependent changes in synaptic plasticity.

Effect of a single oral dose of 600,000 IU of cholecalciferol on serum calciotropic hormones in young subjects with vitamin D deficiency: a prospective intervention study.

CONTEXT: Effects of vitamin D repletion in young people with low vitamin D status have not been investigated so far. OBJECTIVE: We evaluated the effect of a single massive dose of cholecalciferol on calcium metabolism at 3, 15, and 30 d, compared to baseline. DESIGN AND SETTING: We conducted a prospective intervention study in an ambulatory care setting. PARTICIPANTS: Forty-eight young subjects with vitamin D deficiency participated in the study. INTERVENTION: A single oral dose of 600,000 IU of cholecalciferol was administered to each subject. MAIN OUTCOME MEASURES: We evaluated serum changes of 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D, calcium, and PTH induced by a single load of cholecalciferol. RESULTS: The 25(OH)D level was 15.8 ± 6.5 ng/ml at baseline and became 77.2 ± 30.5 ng/ml at 3 d (P < 0.001) and 62.4 ± 26.1 ng/ml at 30 d (P < 0.001). PTH levels concomitantly decreased from 53.0 ± 20.1 to 38.6 ± 17.2 pg/ml at 3 d and to 43.4 ± 14.0 pg/ml at 30 d (P < 0.001 for both). The trends were maintained in a subgroup followed up to 90 d (P < 0.001). Mean serum Ca and P significantly increased compared to baseline, whereas serum Mg decreased at 3 d. 1,25-Dihydroxyvitamin D significantly increased from 46.8 ± 18.9 to 97.8 ± 38.3 pg/ml at 3 d (P < 0.001) and to 59.5 ± 27.3 pg/ml at 60 d (P < 0.05). CONCLUSIONS: A single oral dose of 600,000 IU of cholecalciferol rapidly enhances 25(OH)D and reduces PTH in young people with vitamin D deficiency.

Regulation of PTH secretion by 25-hydroxyvitamin D and ionized calcium depends on vitamin D status: a study in a large cohort of healthy subjects.

INTRODUCTION: Previous papers investigating vitamin D status have often outlined the significant relationships between serum parathyroid hormone (PTH) and 25-hydroxyvitamin D (25OHD), but the influence of ionized calcium levels has not been concomitantly considered. DESIGN: Cross-sectional. MATERIALS AND METHODS: In 1050 healthy men (547) and women (503), serum ionized calcium (iCa), creatinine (Cr), albumin, 25OHD, and PTH were measured. After conventional analysis, a regression tree was fitted on the data set. RESULTS: 25OHD and PTH values showed significant opposite seasonal changes. 25OHD levels negatively correlated with PTH, which in turn negatively correlated with iCa. A regression tree was fitted to the whole data set using PTH as the response variable and 25OHD and iCa as covariates. PTH concentration depended on that of iCa only in subjects with 25OHD levels>16.35 ng/mL, while for 25OHD<16.35 ng/mL it depended on 25OHD values. CONCLUSIONS: Our results indicated that PTH levels were highly conditioned by those of 25OHD in subjects with 25OHD values lower than 16.35 ng/mL and by those of iCa only for higher 25OHD concentration.

Sporadic and MEN1-related primary hyperparathyroidism: differences in clinical expression and severity.

Primary hyperparathyroidism (PHPT) is a common endocrine disease that is associated with multiple endocrine neoplasia type 1 (MEN1) in approximately 2% of PHPT cases. Lack of a family history and other specific expressions may lead to underestimated MEN1 prevalence in PHPT. The aim of this study was to identify clinical or biochemical features predictive of MEN1 and to compare the severity of the disease in MEN1-related versus sporadic PHPT (sPHPT). We performed a 36-mo cross-sectional observational study in three tertiary referral centers on an outpatient basis on 469 consecutive patients with sporadic PHPT and 64 with MEN1-related PHPT. Serum calcium, phosphate, PTH, 25(OH)D(3), and creatinine clearance were measured, and ultrasound examination of the urinary tract/urography was performed in all patients. In 432 patients, BMD was measured at the lumbar spine (LS) and femoral neck (FN). MEN1 patients showed lower BMD Z-scores at the LS (-1.33 +/- 1.23 versus -0.74 +/- 1.4, p = 0.008) and FN (-1.13 +/- 0.96 versus -0.6 +/- 1.07, p = 0.002) and lower phosphate (2.38 +/- 0.52 versus 2.56 +/- 0.45 mg/dl, p = 0.003) and PTH (113.8 +/- 69.5 versus 173.7 +/- 135 pg/ml, p = 0.001) levels than sPHPT patients. Considering probands only, the presence of MEN1 was more frequently associated with PTH values in the normal range (OR, 3.01; 95% CI, 1.07-8.50; p = 0.037) and younger age (OR, 1.61; 95% CI, 1.28-2.02; p = 0.0001). A combination of PTH values in the normal range plus age <50 yr was strongly associated with MEN1 presence (OR, 13.51; 95% CI, 3.62-50.00; p = 0.0001). In conclusion, MEN1-related PHPT patients show more severe bone but similar kidney involvement despite a milder biochemical presentation compared with their sPHPT counterparts. Normal PTH levels and young age are associated with MEN1 presence.

Spinal volumetric trabecular bone mass in acromegalic patients: a longitudinal study.

OBJECTIVE: Data on trabecular bone mass in acromegaly are controversial. All the studies are cross-sectional and bone mineral density (BMD) has been evaluated largely by dual X-ray absorptiometry (DXA), which is influenced by bone enlargement. In this study we assessed in acromegalic patients the effects overtime of GH excess on trabecular bone mass measured by single-energy quantitative computed tomography (QCT) which is not influenced by bone size. DESIGN: Longitudinal retrospective study. PATIENTS: A total of 46 acromegalic patients followed-up for 48 months (median), subdivided into four groups: group A (eugonadal patients with active disease: n = 13), group B (hypogonadal patients with active disease; n = 9), group C (eugonadal patients with controlled disease; n = 10), group D (hypogonadal patients with controlled disease; n = 14). MEASUREMENTS: Serum GH and IGF-I levels, spinal trabecular BMD, and vertebral fractures were evaluated in all patients. BMD variations were reported as change (Delta) in Z-values (Z-QCT) measured at baseline and end of follow-up per year (Delta Z-QCT). RESULTS: Delta Z-QCT was greater in group A vs. group B and D (P =0.002 and P = 0.0001, respectively) and in group C vs. group D (P =0.009). Multivariate regression analysis showed that hypogonadal status (beta = -0.69; P = 0.001) and baseline duration of hypogonadism (beta = 0.44; P = 0.02) but not baseline duration of acromegaly, length of follow-up and disease activity, were significantly associated with Delta Z-QCT. CONCLUSIONS: This longitudinal study suggests that the effect of chronic GH excess on spinal trabecular bone mass seems to be anabolic in active eugonadal patients but not in hypogonadal ones.

The effects of alendronate treatment in osteoporotic patients affected by monoclonal gammopathy of undetermined significance.

In patients with monoclonal gammopathy of undetermined significance (MGUS) the increase of bone turnover rate can increase the risk of fracture. Thus, a treatment normalizing this negative balance could be of benefit in these patients. We studied 100 patients affected by MGUS, grouped according to the presence (group A, 50 patients) or absence (group B) of vertebral fractures and/or osteoporosis. Group A was treated with alendronate (70 mg/weekly) plus calcium and cholecalciferol for 18 months, and group B was treated with calcium and cholecalciferol. After 18 months, the mean bone mineral density (BMD) of the lumbar spine and total femur had increased by 6.1% and 1.5%, respectively, in group A. In the nine patients of this group not taking alendronate, BMD values of the lumbar spine and total femur decreased by 1.6% (P < or = 0.001 ) and 1.3% (P < or = 0.01), respectively. In patients of group B, BMD increased by 1.2% at the lumbar spine and decreased by 1.2% at the total femur. Corresponding figures of those patients in the same group not taking calcium and vitamin D supplementation were -0.1% and -1.2%, respectively. At 18 months we observed significant decreases of serum bone markers: the difference between the groups was -23.2 (P < or = 0.01) for bone alkaline phosphatase, -23.6 for osteocalcin (P < or = 0.01), -35.1 for C-terminal telopeptides of collagen type I (P < or = 0.001), and -0.47 for bone sialoprotein (P = nonsignificant). Treatment with alendronate could lead to a significant reduction in fracture risk in MGUS patients with skeletal fragility.

Short and long-term variations in serum calciotropic hormones after a single very large dose of ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) in the elderly.

CONTEXT: In humans, few studies have compared the potencies of ergocalciferol and cholecalciferol in improving and maintaining vitamin D status. OBJECTIVE: Our objective was to evaluate the effects of a single very large dose of both calciferols on serum changes of 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)(2)D], ionized calcium, and parathyroid hormone (PTH) at baseline, and at 3, 7, 30, and 60 d. DESIGN: This was a prospective randomized intervention study. SETTING: The study was performed in a nursing home residence. PARTICIPANTS: A total of 32 elderly female patients (age range 66-97 yr), with vitamin D deficiency was included in the study. INTERVENTION: Participants were randomized into four groups of eight to receive a single dose of 300,000 IU ergocalciferol or cholecalciferol by oral (os) or im route. RESULTS: 25(OH)D levels sharply increased at d 3 only when vitamins were given os. The 30-d basal difference in serum 25(OH)D was significantly greater after cholecalciferol os administration (47.8 +/- 7.3 ng/ml) compared with other forms (D(3) im: 15.9 +/- 11.3; D(2) os: 17.3 +/- 4.7; D(2) im: 5 +/- 4.4; all P < 0.001). The area under the curve (AUC) of the serum 25(OH)D against time (AUC(60)) was: D(3) os, 3193 +/- 759 ng x d/ml vs. D(2) os, 1820 +/- 512, P < 0.001; and D(3) im, 1361 +/- 492 vs. D(2) im, 728 +/- 195, P < 0.01. 25(OH)D significantly influences PTH levels at 3 (P < 0.03), 7 (P < 0.01), 30 (P < 0.01), and 60 d (P < 0.05). At 60 d, the form of vitamin (cholecalciferol) significantly lowers PTH levels (P = 0.037). CONCLUSIONS: Cholecalciferol is almost twice as potent as ergocalciferol in increasing serum 25(OH)D, when administered either by mouth or im. 25(OH)D plays a role in modulating serum PTH.

Subclinical hypercortisolism among outpatients referred for osteoporosis.

BACKGROUND: Hypercortisolism is known to cause osteoporosis. OBJECTIVE: To evaluate the prevalence of subclinical hypercortisolism in participants referred for evaluation of osteoporosis. DESIGN: Cross-sectional study. SETTING: Two community hospitals and research institutes in Italy. PATIENTS: 219 patients without clinically overt hypercortisolism or other secondary causes of osteoporosis who were referred for evaluation of osteoporosis between January 2005 and December 2005. MEASUREMENTS: Bone mineral density was measured by using dual-energy x-ray absorptiometry, and hypercortisolism was assessed with serum cortisol levels after a dexamethasone suppression test. Also measured were 24-hour urinary free cortisol levels and midnight plasma cortisol levels. RESULTS: Seven of 65 patients with T-scores of 2.5 or less and vertebral fractures had subclinical hypercortisolism (prevalence, 10.8% [95% CI, 3.23% to 18.31%]). This prevalence was 4.8% (CI, 1.32% to 8.20%) among patients with osteoporosis. In multivariable analyses adjusted for age, sex, and body mass index, a positive dexamethasone suppression test result was associated with the presence of osteoporosis (odds ratio, 3.37 [CI, 1.78 to 6.43]; P < 0.001) and vertebral fractures (odds ratio, 1.70 [CI, 1.04 to 2.79]; P = 0.035). LIMITATIONS: The study was conducted in a referral setting; its findings may not apply to the general population. CONCLUSIONS: Subclinical hypercortisolism may be more common than is generally recognized in patients with osteoporosis in whom secondary causes of osteoporosis have been excluded.

Primary hyperparathyroidism and the presence of kidney stones are associated with different haplotypes of the calcium-sensing receptor.

INTRODUCTION: Three single-nucleotide polymorphisms in the calcium-sensing receptor gene (CASR) encoding the missense substitutions A986S, R990G, and Q1011E have been associated with normal variation in extracellular calcium homeostasis, both individually and in haplotype combination. The aim of this study was to examine haplotype associations in primary hyperparathyroidism (PHPT). PATIENTS AND METHODS: Patients with sporadic PHPT (n = 237) were recruited from endocrine clinics and healthy controls (n = 433) from a blood donor clinic, and levels of serum calcium, albumin, and PTH were measured. In PHPT patients, urinary calcium/creatinine clearances and bone mineral density at spine and femoral neck were measured and the presence of kidney stones and vertebral fractures identified. The CASR single-nucleotide polymorphisms were haplotyped by allele-specific sequencing. RESULTS: Four haplotypes (ARQ, SRQ, AGQ, and ARE) of eight were observed, in keeping with significant linkage disequilibrium, but haplotype frequencies did not show significant Hardy-Weinberg disequilibrium. The SRQ haplotype was more common in PHPT (125 of 474 alleles) than in controls (170 of 866 alleles, P = 0.006) and showed a significant (P = 0.006) gene-dosage effect. There was no significant association between haplotype and bone mineral density or fractures, but association with kidney stones was significant (P = 0.0007). In the stone-forming subgroup, the SRQ haplotype was underrepresented and AGQ overrepresented. Patients bearing the AGQ haplotype had an odds ratio of 3.8 (95% confidence interval, 1.30-11.3) for presentation with renal stones compared with the rest. CONCLUSION: Our data indicate that the CASR SRQ haplotype is significantly associated with PHPT in our population. Within the PHPT patient population, the AGQ haplotype is significantly associated with kidney stones.

HOXA1 gene variants influence head growth rates in humans.

We previously described a significant association between the HOXA1 G218 allele and increased head circumference in autism [Conciatori et al. (2004); Biol Psychiatry 55:413-419]. The present study reveals identical effects also in normal children. HOXA1 A218G alleles and sex explain as much as 10.9 and 6.8% of the variance in head circumference in 142 pediatric controls and in 191 autistic children, aged 3-16 years (F = 6.777, 3 and 141 df, P < 0.001 and F = 5.588, 3 and 190 df, P < 0.01, respectively). Instead, no association is found in 183 adult controls and in 35 pediatric fragile-X patients. Therefore HOXA1 A218G alleles significantly influence head growth rates, but not final head size, in normal human development. This influence does not differ between normal and autistic children, whereas the lack of FMRP seemingly overwhelms HOXA1 effects in fragile-X patients.

Vitamin D status in inpatients admitted to an internal medicine department.

BACKGROUND/AIMS: A role of hypovitaminosis D has been advocated in several medical conditions. We investigated vitamin D status in medical inpatients, compared to a blood donors' group from the same area. METHODS: Fifty-nine consecutive medical patients were recruited at hospital admission, concomitantly to 207 blood donors of both genders. Serum calcium, albumin, phosphate, creatinine, alkaline phosphatase total activity, 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) were assessed from April to May 2005. RESULTS: In patients, 25(OH)D values were lower (13.1 +/- 9.2 vs. 16.3 +/- 8.5 ng/ml; p < 0.02) and PTH values higher (73.9 +/- 77.7 vs. 53.4 +/- 24.3 pg/ml; p < 0.01) than in controls, whose mean age was lower (62.5 +/- 14.5 vs. 45.8 +/- 15.6 years, p < 0.01). Such differences were not confirmed when comparing patients to a subgroup of age and sex-matched controls drawn from the whole sample of blood donors. In both patients and controls there was a trend towards a negative correlation between 25(OH)D and age and a positive correlation between PTH and age. The prevalence of 25(OH)D <12 ng/ml was higher in patients than in controls as a whole (58 vs. 34%; chi(2) = 9.95; p < 0.002), but not in respect to the subgroup of matched controls (58 vs. 44%; chi(2) = 2.09; p = 0.14). The prevalence of severe vitamin D deficiency, 25(OH)D <5 ng/ml, was significantly higher in patients than in matched controls (17 vs. 4%; chi(2) = 6.75; p < 0.01). CONCLUSION: Hypovitaminosis D, defined as 25(OH)D <12 ng/ml, is frequent among inpatients, as in the general population of comparable age. A severe vitamin D deficiency is more common in hospitalized patients.

Diagnosis of parathyroid tumors in familial isolated hyperparathyroidism with HRPT2 mutation: implications for cancer surveillance.

CONTEXT: Mutations of the HRPT2 gene have recently been implicated in the development of parathyroid carcinoma. OBJECTIVE: The objective of this study was early diagnosis of parathyroid tumor in a family with germline HRPT2 mutation. PATIENTS, METHODS, AND RESULTS: In a 40-yr-old male previously treated for parathyroid atypical adenoma, we screened the 17 translated HRPT2 exons and their exon-intron boundaries and found a germline frameshift mutation in exon 7 (685delAGAG) predicting a premature stop codon at nucleotides 767-769. Nine family members (age, 33.9 +/- 19.8 yr, mean +/- SD) also carry the mutation, but eight have had normal serum calcium. Biochemical and ultrasonographic evaluation uncovered a 27-yr-old hypercalcemic carrier niece with an atypical parathyroid adenoma, and a 43-yr-old normocalcemic carrier sister was found by ultrasonography to have an extrathyroidal nodule, which proved to be parathyroid carcinoma. The index case, 12 yr after surgery, was normocalcemic, but ultrasonography revealed an extrathyroidal nodule in the contralateral hemithyroid tissue that proved to be atypical adenoma. CONCLUSIONS: Our report confirms that germline mutations of HRPT2 gene may be associated with multiple parathyroid neoplasms. Our experience suggests that longitudinal surveillance by serum biochemistry alone may not be 100% sensitive, and addition of routine neck ultrasonography is a readily accepted adjunct that may facilitate earlier disease detection in some families.

The relationship of vitamin D status to bone mineral density in an Italian population of postmenopausal women.

Several authors have found a relationship between vitamin D status and bone mineral density (BMD). To our knowledge, no previous studies on this topic have been carried out on the Italian postmenopausal population. We studied this relationship retrospectively in 156 Italian postmenopausal women. We also investigated the relationship between parathyroid hormone (PTH) and BMD. Measurements of BMD were taken at the lumbar spine and upper femur by dual X-ray absorptiometry. Serum 25(OH)D (calcidiol), 1,25(OH)2D (calcitriol), PTH, calcium, phosphorus, creatinine, osteocalcin and urinary calcium and phosphorus were measured according to the current laboratory methods of analysis. We found a positive statistically significant correlation between BMD, both at the spine and hip, and 25(OH)D, and a negative statistically significant correlation between BMD and PTH. No statistically significant correlation was found between BMD and 1,25(OH)2D. Crude logistic regression showed age, 25(OH)D and PTH were significant predictors of low BMD, while 1,25(OH)2D was not. Backward logistic regression showed 25(OH)D was the best predictive model for spine osteoporosis together with age, and on its own it was the best predictive model for femoral neck osteoporosis.