Bone mineral density in primary care patients related to serum calcium concentrations: a longitudinal cohort study from Sweden.

OBJECTIVE: Elevated calcium concentration is a commonly used measure in screening analyses for primary hyperparathyroidism (pHPT) and cancer. Low bone mineral density (BMD) and osteoporosis are common features of pHPT and strengthen the indication for parathyroidectomy. It is not known whether an elevated calcium concentration could be a marker of low BMD in suspected pHPT patients with a normal parathyroid hormone concentration. PURPOSE: To study if low BMD and osteoporosis are more common after ten years in patients with elevated compared with normal calcium concentrations at baseline. DESIGN: Prospective case control study. SETTING: Primary care, southern Sweden. SUBJECTS: One hundred twenty-seven patients (28 men) with baseline elevated, and 254 patients (56 men) with baseline normal calcium concentrations, mean age 61 years, were recruited. After ten years, 77% of those still alive (74 with elevated and 154 with normal calcium concentrations at baseline) participated in a dual energy x-ray absorptiometry measurement for BMD assessment and analysis of calcium and parathyroid hormone concentrations. MAIN OUTCOME MEASURES: Association between elevated and normal calcium concentration at base-line and BMD at follow-up. Correlation between calcium and parathyroid hormone concentrations and BMD at follow-up. RESULTS: A larger proportion of the patients with elevated baseline calcium concentrations who participated in the follow-up had osteoporosis (p value = 0.036), compared with the patients with normal concentrations. In contrast, no correlation was found between calcium or parathyroid hormone concentrations and BMD at follow-up. CONCLUSIONS: In this study, patients with elevated calcium concentrations at baseline had osteoporosis ten years later more often than controls (45% vs. 29%), which highlights the importance of examining these patients further using absorptiometry, even when their parathyroid hormone level is normal. Key Points Osteoporosis is common, difficult to detect and usually untreated. It is not known whether elevated calcium concentrations, irrespective of the PTH level, could be a marker of low bone mineral density. No correlation was found between calcium or parathyroid hormone concentrations and bone mineral density at follow-up. In this study, patients with elevated calcium concentrations at baseline had osteoporosis ten years later more often than controls (45% vs. 29%).

The association between the IGF-I axis, thyroid hormones and cortical bone in patients with mild primary hyperparathyroidism.

OBJECTIVES: Primary hyperparathyroidism (PHPT) is associated with low bone mineral density (BMD) and increased risk of osteoporotic fractures. This study investigated whether the IGF-I axis and thyroid hormones are associated with BMD and osteoporotic fractures before and after parathyroidectomy (PTX). MATERIALS AND METHODS: Forty-five patients with mild PHPT were examined before and 1 year after PTX. Circulating concentrations of IGF-1, IGFBP-3, and thyroid hormones were measured and related to BMD in hip and lumbar (L:2-L:4) spine. RESULTS: Serum IGFBP-3 concentration decreased 1 year after PTX (p < 0.01), whereas serum IGF-1 and thyroid hormone concentrations were unchanged. Serum IGF1 concentration correlated positively with IGFBP-3 concentration (p < 0.0001) and BMD in the femoral neck (p < 0.05), both pre- and postoperatively. Serum IGFBP-3 concentration correlated positively with BMD in the femoral neck postoperatively (p < 0.05). Serum TSH correlated positively, and free thyroxine (T4) negatively, with all measures of hip BMD at baseline. Patients suffering from previous osteoporotic fractures before inclusion had lower serum TSH concentration compared to patients without fractures (p < 0.01). CONCLUSION: Serum IGFBP-3 concentration decreased after successful PTX in patients with mild PHPT, while serum IGF1 and thyroid hormone concentrations were unchanged. Both the IGF-I axis and thyroid hormones associated with cortical bone as serum IGF-1 and IGFBP-3 concentrations correlated positively, and free T4 negatively with hip BMD. Moreover, serum TSH concentration was reduced in patients with previous osteoporotic fractures.

Long-term follow-up of patients with elevated serum calcium concentrations in Swedish primary care.

OBJECTIVE: To follow up patients with elevated calcium concentrations after 10 years. DESIGN: Longitudinal, using medical records, questionnaires, and clinical investigation. SETTING: Primary care in Tibro, Sweden, 2008-2010. SUBJECTS: 127 patents with elevated calcium concentrations and 254 patients with normal calcium concentrations from the local community, attending the health care centre. MAIN OUTCOME MEASURES: Diagnoses and mortality in patients with elevated calcium concentrations in 1995-2000, compared with patients with normal calcium concentrations and the background population. RESULTS: The proportion of patients for whom no underlying cause was detected decreased from 55% at baseline to 12% at follow-up. Primary hyperparathyroidism was most common in women, 23% at baseline and 36% at follow-up, and the cancer prevalence increased from 5% to 12% in patients with elevated calcium concentration. Mortality tended to be higher in men with elevated calcium concentrations compared with men with normal calcium concentrations, and was significantly higher than in the background population (SMR 2.3, 95% CI 1.3-3.8). Cancer mortality was significantly increased in men (p = 0.039). Low calcium concentrations were also associated with higher mortality (p = 0.004), compared with patients with normal calcium concentrations. CONCLUSION: This study underscores the importance of investigating patients with increased calcium concentrations suggesting that most of these patients--88% in our study--will turn out to have an underlying disease associated with hypercalcaemia during a 10-year follow-up period. Elevated calcium concentrations had a different disease pattern in men and women, with men showing increased cancer mortality in this study.

Factors influencing insulin sensitivity in patients with mild primary hyperparathyroidism before and after parathyroidectomy.

OBJECTIVES: Primary hyperparathyroidism (PHPT) is associated with cardiovascular disease. The aims of this study were to investigate lipid and glucose metabolism in mild PHPT, and to identify whether insulin sensitivity correlates with circulating levels of adiponectin, SHBG, and osteocalcin before and after parathyroidectomy (PTX). MATERIALS AND METHODS: Forty-five patients with PHPT were examined before and 1 year after PTX. Circulating levels of triglycerides, total cholesterol, HDL-cholesterol, insulin, glucose, adiponectin, SHBG, osteocalcin, and erythropoietin were measured. RESULTS: At baseline, the mean serum levels of total cholesterol, LDL-cholesterol and triglycerides were above the upper reference limit or in the upper normal range, and insulin sensitivity was reduced as assessed using the HOMA index. One year after parathyroidectomy, serum lipids as well as HOMA index and erythropoietin were unchanged while adiponectin had increased (p < 0.05), and SHBG and osteocalcin had decreased (p < 0.05 and p < 0.0001, respectively). HOMA index correlated negatively with circulating levels of adiponectin, SHBG and osteocalcin. In multiple regression analysis SHBG was the most important predictor of insulin sensitivity, both pre- and postoperatively. CONCLUSION: Untreated mild PHPT is associated with a moderate derangement of lipid and glucose metabolism. As previously shown in population-based cohorts, insulin sensitivity is positively associated with circulating concentrations of adiponectin, SHBG and osteocalcin. One year after PTX, the mean level of adiponectin was increased, but the levels of SHBG and osteocalcin had decreased and the levels of serum lipids and the insulin sensitivity remained unchanged as compared with baseline.

Increased markers of inflammation and endothelial dysfunction in patients with mild primary hyperparathyroidism.

OBJECTIVES: The association between primary hyperparathyroidism (PHPT) and cardiovascular disease is incompletely understood. The aims of this study were to evaluate how cardiac function and markers of inflammation and endothelial dysfunction correlate in patients with mild PHPT, and how these markers are influenced by surgical cure of the parathyroid disease (PTX). MATERIAL AND METHODS: Forty-five patients with PHPT were examined before and 1 year after PTX. Serum/plasma concentrations of calcium, PTH, highly sensitive C-reactive protein (CRP), interleukin-6 (IL-6), vascular adhesion molecule-1 (VCAM1), E-selectin, and NT-proBNP were measured as well as erythrocyte sedimentation rate (ESR) and creatinine clearance. Cardiac function was evaluated by equilibrium radionuclide angiography. RESULTS: The baseline serum level of IL-6 correlated negatively with baseline parameters of cardiac function (exercise capacity, p < 0.001, left ventricular ejection fraction at exercise, p < 0.01). The mean serum concentrations of IL-6 and CRP and the ESR had increased 1 year after PTX (p < 0.001, p < 0.01, and p < 0.001, respectively) in parallel with a decrease in cardiac function and an increase in circulating NT-proBNP. The mean serum level of VCAM1 was above the upper normal range at baseline and had not changed significantly 1 year after PTX. CONCLUSION: Patients with mild PHPT and normal renal function displayed signs of subclinical inflammation and endothelial dysfunction. One year after PTX, the inflammatory markers were increased in parallel with a subclinical decrease in cardiac function. Further studies are warranted to clarify the natural course and clinical implications of these changes.

Reduced cerebrospinal fluid concentration of interleukin-12/23 subunit p40 in patients with cognitive impairment.

BACKGROUND: The role of inflammation in Alzheimer's disease (AD) and other cognitive disorders is unclear. In a well-defined mono-center population, we measured cytokines and chemokines in paired serum and cerebrospinal fluid (CSF) samples. METHODS: Consecutive patients with AD (n = 30), stable mild cognitive impairment (SMCI, n = 11), other dementias (n = 11), and healthy controls (n = 18) were included. None of the subjects was treated with glucocorticoids, cholinesterase inhibitors, or non-steroidal anti-inflammatory drugs. Serum and CSF concentrations of interleukin-6 (IL-6), IL-8, IL-12/23 p40, IL-15, IL-16, vascular endothelial growth factor-A (VEGF-A), and three chemokines were measured using a multiplex panel. RESULTS: After correction for multiple comparisons, only CSF IL-12/23 p40 concentration differed significantly between the total patient group (n = 52) and controls (n = 18; p = 0.002). Further analyses showed that CSF IL-12/23 p40 concentration was decreased in all patient subgroups (AD, other dementias, and SMCI) compared to healthy controls (p < 0.01, p < 0.05, and p < 0.05, respectively). In the total study population (n = 70), CSF IL-12/23 p40 concentrations correlated positively with CSF concentrations of ß-amyloid1-42 (Aß1-42) and phosphorylated tau protein (P-tau) whereas in AD patients (n = 30), CSF IL-12/23 p40 only correlated positively with CSF P-Tau (r = 0.46, p = 0.01). CONCLUSIONS: Most cytokines and chemokines were similar in patients and controls, but CSF IL-12/23 subunit p40 concentration was decreased in patients with cognitive impairment, and correlated with markers of AD disease status. Further studies are needed to evaluate the role of CSF IL-12/23 p40 in other dementias and SMCI.

Reduced Cerebrospinal Fluid Concentration of Apolipoprotein A-I in Patients with Alzheimer's Disease.

BACKGROUND: Apolipoprotein E (ApoE) has been extensively studied in Alzheimer's disease (AD), but little is known of apolipoprotein A-I (ApoA-I) in cerebrospinal fluid (CSF). OBJECTIVE: Plasma lipids as well as ApoA-I and ApoE in plasma and CSF were determined and related to Mini-Mental State Examination (MMSE) score, APOE genotype, and CSF AD biomarkers. METHODS: Consecutive patients with AD (n = 29), stable mild cognitive impairment (n = 13), other dementias (n = 14), and healthy controls (n = 18) were included at a single center. RESULTS: AD patients had higher plasma triglycerides and lower CSF ApoA-I concentration than controls (both p < 0.05). CSF ApoE concentration was reduced in other dementias (p < 0.01). In AD as well as other dementias, the ratios between CSF and plasma concentrations of both ApoA-I and ApoE were lower than those in the controls. ApoA-I and ApoE in plasma and CSF were not influenced by APOEɛ4 allele distribution. In the total study population (n = 74), CSF ApoA-I correlated positively with MMSE score (r = 0.26, p < 0.05) and negatively with CSF P-tau (r = -0.25, p < 0.05). CSF ApoE correlated positively with CSF concentrations of T-tau and P-tau in the total study population and in AD patients. CONCLUSION: CSF ApoA-I was reduced in AD patients and associated with measures of cognitive function and AD disease status. The mechanisms underlying the decreased CSF:plasma ratios of ApoA-I and ApoE in AD and other dementias need to be explored in further studies.

Body composition and bone mineral density in women with Cushing's syndrome in remission and the association with common genetic variants influencing glucocorticoid sensitivity.

OBJECTIVE: Adverse body compositional features and low bone mineral density (BMD) are the characteristic of patients with active Cushing's syndrome (CS). The aim of this study was to evaluate body composition and BMD in women with CS in long-term remission and the influence of polymorphisms in genes affecting glucocorticoid (GC) sensitivity on these end-points. DESIGN, PATIENTS AND METHODS: This was a cross-sectional, case-controlled study, including 50 women previously treated for CS and 50 age and gender-matched controls. Median (interquartile range) remission time was 13 (5-19) years. Body composition and BMD were measured with dual-energy X-ray absorptiometry. Five polymorphisms in four genes associated with GC sensitivity were analysed using TaqMan or Sequenom single-nucleotide polymorphism genotyping. RESULTS: Patients with CS in remission had increased abdominal fat mass (P<0.01), whereas BMD was not significantly different at any site between patients and controls. In patients, the NR3C1 Bcl1 polymorphism was associated with reduced total (P<0.05) and femur neck BMD (P<0.05). The polymorphism rs1045642 in the ABCB1 gene was associated with increased abdominal fat mass (P<0.05) and decreased appendicular skeletal muscle mass (P<0.05). GC replacement was associated with reduced total BMD (P<0.01), BMD at lumbar spine (P<0.05) and increased abdominal fat (P<0.01). CONCLUSION: Ongoing GC replacement therapy together with polymorphisms in two genes related with GC sensitivity is associated with abdominal obesity and adverse skeletal health in patients with CS in long-term remission.

Cerebrospinal fluid substance P concentrations are elevated in patients with Alzheimer's disease.

The neuropeptides substance P, orexin A (hypocretin-1) and neurotensin are signaling molecules that influence brain activity. We examined their cerebrospinal fluid (CSF) levels in a study population consisting of Alzheimer's disease (AD) dementia or mild cognitive impairment (MCI) diagnosed with AD dementia upon follow-up (n=32), stable MCI (SMCI, n=13), other dementias (n=15), and healthy controls (n=20). CSF substance P level was increased in AD patients compared to patients with other dementias and healthy controls (P<0.05 and P<0.01, respectively). Patients with other dementia or SMCI had lower CSF orexin A level than AD patients (both P<0.05) and marginally lower level than healthy controls (both P=0.05). CSF neurotensin level was similar in all groups. In the total study population (n=80), CSF substance P level correlated positively with CSF levels of T-tau and P-tau, and in AD patients (n=32), CSF substance P level correlated positively with CSF Aß1-42 level. In conclusion, CSF substance P level was elevated in AD patients and correlated with CSF Aß1-42 level, a well established marker of senile plaque pathology. The role of low CSF orexin A level in other dementias or SMCI needs to be explored in further studies.

Cardiac dysfunction in mild primary hyperparathyroidism assessed by radionuclide angiography and echocardiography before and after parathyroidectomy.

BACKGROUND: Primary hyperparathyroidism (PHPT) is associated with increased cardiovascular morbidity for reasons that are incompletely understood. The present study was undertaken to evaluate the effects of parathyroidectomy on cardiac function especially in patients with mild PHPT. METHODS; Fifty patients with mild PHPT (serum calcium, 2.55 to 2.95 mmol/L) were randomized to parathyroidectomy either directly (group A) or after 1 year of observation (group B). Equilibrium radionuclide angiography (ERNA) at rest and at exercise was performed in addition to echocardiography on all patients at inclusion in the study and 1 and 2 years later. RESULTS: Left ventricular mass index was larger (P <.05) in group B compared with group A after 2 years and showed significant correlation to the serum concentration of parathyroid hormone (but not serum calcium) after 1 year. ERNA showed transient subclinical changes in both systolic and diastolic function parameters after parathyroidectomy (decrease of left ventricular ejection fraction and peak filling rate, with return to preoperative levels within 1 year). CONCLUSIONS: Combined evaluation by ERNA and echocardiography has shown previously unknown aspects of parathyroid/myocardial interaction, which is consistent with an inotropic influence exerted by parathyroid hormone, and is in favor of early surgical treatment for PHPT irrespective of serum calcium levels.

Early parathyroidectomy increases bone mineral density in patients with mild primary hyperparathyroidism: a prospective and randomized study.

BACKGROUND: There is an ongoing controversy regarding how to take care of patients with mild primary hyperparathyroidism (PHPT) and how to grade their disease activity in terms of bone parameters. This prospective and randomized study was undertaken to evaluate skeletal effects of delayed surgical treatment in such patients. METHODS: Fifty patients with mild PHPT (serum calcium, 2.55 to 2.95 mmol/L; 10.2 to 11.8 mg/dL) were randomized to parathyroidectomy either at diagnosis or 1 year later. Hip and spine bone mineral density (BMD, determined by dual energy x-ray absorptiometry), bone alkaline phosphatase in serum, osteocalcin and beta-CrossLaps in plasma, and calcium in urine were measured in all patients at inclusion in the study and 1 and 2 years later. RESULTS: The skeletal effects of mild PHPT varied with anatomy and time of exposure. Parathyroidectomy decreased all biochemical bone markers ( P < .0001) and increased lumbar spine BMD ( P < .05) equally in both groups, even in patients without overt osteoporosis, whereas hip BMD was increased ( P < .05) in the early intervention group only. CONCLUSION: Prolonged exposure to mild and seemingly stable PHPT is a risk factor for hip fractures, which adds to other reasons for surgical treatment of this condition without delay regardless of serum calcium levels.

Cerebrospinal fluid (CSF) 25-hydroxyvitamin D concentration and CSF acetylcholinesterase activity are reduced in patients with Alzheimer's disease.

BACKGROUND: Little is known of vitamin D concentration in cerebrospinal fluid (CSF) in Alzheimer's disease (AD) and its relation with CSF acetylcholinesterase (AChE) activity, a marker of cholinergic function. METHODS: A cross-sectional study of 52 consecutive patients under primary evaluation of cognitive impairment and 17 healthy controls. The patients had AD dementia or mild cognitive impairment (MCI) diagnosed with AD dementia upon follow-up (n = 28), other dementias (n = 12), and stable MCI (SMCI, n = 12). We determined serum and CSF concentrations of calcium, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), and CSF activities of AChE and butyrylcholinesterase (BuChE). FINDINGS: CSF 25OHD level was reduced in AD patients (P < 0.05), and CSF AChE activity was decreased both in patients with AD (P < 0.05) and other dementias (P < 0.01) compared to healthy controls. None of the measured variables differed between BuChE K-variant genotypes whereas the participants that were homozygous in terms of the apolipoprotein E (APOE) ε4 allele had decreased CSF AChE activity compared to subjects lacking the APOE ε4 allele (P = 0.01). In AD patients (n=28), CSF AChE activity correlated positively with CSF levels of total tau (T-tau) (r = 0.44, P < 0.05) and phosphorylated tau protein (P-tau) (r = 0.50, P < 0.01), but CSF activities of AChE or BuChE did not correlate with serum or CSF levels of 25OHD. CONCLUSIONS: In this pilot study, both CSF 25OHD level and CSF AChE activity were reduced in AD patients. However, the lack of correlations between 25OHD levels and CSF activities of AChE or BuChE might suggest different mechanisms of action, which could have implications for treatment trials.

Reduced cerebrospinal fluid level of thyroxine in patients with Alzheimer's disease.

BACKGROUND: Little is known of the association between thyroid hormones in the central nervous system and Alzheimer's disease (AD). We determined thyroid hormone levels in serum and cerebrospinal fluid (CSF) in a well-defined homogeneous mono-center population. METHODS: Fifty-nine consecutive patients under primary evaluation for cognitive impairment were recruited. The participants included patients with AD or mild cognitive impairment (MCI) diagnosed with AD upon follow-up (n=31), patients with stable MCI (SMCI, n=13), patients with other dementias (n=15), and healthy controls (n=19). Thyroid hormones in serum and CSF and AD biomarkers in CSF were analyzed using established immunochemical assays. Cognitive impairment was estimated using mini-mental state examination (MMSE). RESULTS: Serum levels of free and total thyroxine (T4) and triiodothyronine (T3) were similar in all groups whereas a marginal increase in serum thyroid-stimulating hormone (TSH) level was observed in the AD patients. The CSF level of total T4 was decreased in patients with AD and other dementias compared to SMCI (both P=0.01) and healthy controls (both P=0.001), whereas CSF levels of TSH and total T3 were unchanged. In the total study population, CSF total T4 level correlated positively with MMSE score (r=0.26, P<0.05) and negatively with CSF total-tau (T-Tau) level (r=-0.23, P<0.05). CONCLUSION: Patients with AD as well as other dementias had signs of mild brain hypothyroidism, which could only to a small extent be detected in serum values.

Increase of bioavailable testosterone is associated with gain in bone mineral density after cure of primary hyperparathyroidism in postmenopausal women.

OBJECTIVE: The recovery of bone mineral density (BMD) after surgical cure of primary hyperparathyroidism (PHPT) seems to be multifactorial and not just dependent on declining PTH. The aim of the present study was to evaluate the role of sex steroids in this context. DESIGN AND PATIENTS: Thirty-six postmenopausal women with PHPT were examined before and 1 year after curative parathyroidectomy. Their mean age at inclusion in the study was 71.7 +/- 1.1 years (range 54-83). BMD was measured in hip and lumbar spine using dual energy X-ray absorptiometry. No patient received any replacement therapy with sex hormones or treatment with corticosteroids, oestrogen receptor modulators or bisphosphonates. MEASUREMENTS: Serum concentrations of oestradiol, testosterone, androstenedione, dehydroepiandrosterone sulphate, SHBG, PTH and calcium. RESULTS: Postoperative increase of free (bioavailable) testosterone was positively correlated to the change of BMD in the hip (P < 0.01), whereas the change of PTH in serum correlated to the change of BMD in the lumbar spine (P < 0.05). Multiple regression analysis showed that bioavailable testosterone was the most important determinant of change in BMD in both spine and hip (femoral neck: P < 0.05; Ward's triangle: P < 0.001; trochanter: P < 0.01; lumbar spine: P < 0.05). The increase of bioavailable testosterone after curative parathyroidectomy was related to declining SHBG. CONCLUSIONS: An increase of bioavailable testosterone following surgical cure of PHPT is related to improvement of hip and lumbar spine BMD in postmenopausal women. This previously unknown hormonal interaction may also be important to other aspects of hyperparathyroidism.

Increased plasma concentrations of N-terminal pro-B-type natriuretic peptide in patients with mild primary hyperparathyroidism.

OBJECTIVE: Primary hyperparathyroidism (PHPT) is associated with heart disease. The aims of the present study were to evaluate how cardiac function and secretion of N-terminal pro-B-type natriuretic peptide (NT-proBNP) correlate in patients with mild PHPT, and how the plasma level of NT-proBNP is influenced by cure of the parathyroid disease. DESIGN AND PATIENTS: Forty-two patients with PHPT without symptoms of heart disease were examined before and 1 year after curative parathyroidectomy. MEASUREMENTS: Plasma or serum concentrations of NT-proBNP, calcium, PTH, creatinine, oestradiol, testosterone and SHBG were measured. Cardiac function was evaluated by equilibrium radionuclide angiography (ERNA). RESULTS: At baseline, NT-proBNP levels correlated negatively with systolic function [left ventricular ejection fraction (LVEF), P < 0.001]. Twelve per cent of the patients had NT-proBNP levels above normal reference values preoperatively. One year postoperatively, the corresponding proportion was 21%. The mean plasma concentration of NT-proBNP increased after parathyroidectomy (P < 0.01) in parallel with a dip in diastolic function (peak filling rate, P < 0.05) and a falling trend in systolic function (LVEF, P = 0.08). The postoperative percentage changes in circulating NT-proBNP and total oestradiol correlated positively (P < 0.05). CONCLUSIONS: Patients with mild PHPT and normal renal function may have high levels of circulating NT-proBNP despite the absence of symptomatic heart disease. Cure of the parathyroid disease is followed by a further increase in NT-proBNP secretion in parallel with ERNA measures, indicating subclinical changes in heart function. These results are in line with data indicating an association between PHPT and increased risk of premature death.