Ylva Pernow

Effect of Surgery on Cardiovascular Risk Factors in Mild Primary Hyperparathyroidism

CONTEXT Mild primary hyperparathyroidism (pHPT) seems to have a good prognosis, and indications for active treatment (surgery) are widely discussed. The extraskeletal effects of PTH, such as insulin resistance, arterial hypertension, and cardiovascular (CV) risk, may however be reversible by operation. OBJECTIVE Our aim was to study biochemical markers of bone turnover, indices of the metabolic syndrome, and various risk markers for CV disease in patients with mild pHPT randomized to observation without surgery or operative treatment and followed for 2 yr. DESIGN/SETTING/PATIENTS A total of 116 patients (mean age, 63 +/- 8 yr; 19 men and 97 women) who on May 1, 2008, had performed the 2-yr visit in a randomized study on mild pHPT (serum calcium at baseline, 2.69 +/- 0.11 mmol/liter) and where frozen samples were available from baseline and follow-up participated in the study. RESULTS Calcium and PTH levels were normalized after surgery, and biochemical markers of bone turnover decreased by 35%, followed by a significant increase in BMD in the spine (2.7%; P < 0.01) and femoral neck (1.1%; P < 0.02) compared with the observation group. No significant differences were observed between the groups for blood pressure, markers of insulin resistance, detailed cholesterol metabolism, adipokines, or parameters of inflammation and CV surrogate markers. CONCLUSIONS We observed expected effects on biochemical markers of bone turnover and bone mass after surgical treatment of mild pHPT, with stable values in the group randomized to observation. For a variety of measures of the metabolic syndrome, adipokines, and CV risk factors, no benefit of operative treatment could be demonstrated. Neither did we observe any deleterious effects of conservative management in the 2-yr perspective.

Osteoblast Dysfunction in Male Idiopathic Osteoporosis

The etiology of primary osteoporosis in young and middle-aged men is unknown. We have studied osteoblast function in cells derived from men with idiopathic osteoporosis and in control cells from age-matched men with osteoarthrosis. Osteoblasts were isolated from transiliac bone biopsies. Osteoblast function was measured as vitamin D-stimulated osteocalcin production and production of cytokines and factors involved in osteoclast activation and bone formation. Cell proliferation was measured as 3H-thymidine incorporation. Parathyroid hormone-related peptide (PTHrP) mRNA was measured using reverse-transcriptase polymerase chain reaction. In osteoporotic men, bone mineral density at the femoral neck was correlated to in vitro production of osteocalcin. Osteoblasts from osteoporotic men produced significantly less osteocalcin after vitamin D stimulation but had increased production of macrophage colony-stimulating factor (M-CSF) compared to controls. The osteocalcin response was negatively correlated to production of M-CSF, interleukin-6, and C-terminal propeptide of type I collagen. Basal 3H-thymidine incorporation was similar in cells from osteoporotic patients and controls. PTHrP (10−9 M) significantly increased cell proliferation in control cells but not in osteoporotic cells. Basal PTHrP mRNA levels were significantly higher in osteoporotic cells than in cells from controls. The results are in agreement with previous histomorphologic studies indicating that men with idiopathic osteoporosis have an osteoblast dysfunction with decreased osteocalcin production and increased production of factors stimulating osteoclast activation. This indicates a catabolic cellular metabolic balance leading to negative bone turnover, resulting in osteoporosis. The cause of such cellular dysfunction needs further evaluation.

Effects of Parathyroidectomy Versus Observation on the Development of Vertebral Fractures in Mild Primary Hyperparathyroidism

CONTEXT Mild primary hyperparathyroidism (PHPT) is a common disease especially in middle-aged and elderly women. The diagnosis is frequently made incidentally and treatment strategies are widely discussed. OBJECTIVE To study the effect of parathyroidectomy (PTX) compared with observation (OBS) on biochemistry, safety, bone mineral density (BMD), and new fractures. DESIGN Prospective, randomized controlled study (SIPH study), with a 5-year follow-up. SETTING The study was conducted at multicenter, tertiary referral centers. PATIENTS Of 191 randomized patients with mild PHPT, biochemical data were available for 145 patients after 5 years, with a mean age at inclusion of 62.8 years (OBS group, 9 males) and 62.1 years (PTX group, 10 males). INTERVENTION Parathyroidectomy vs observation. MAIN OUTCOME MEASURES Biochemistry, BMD, and new radiographic vertebral fractures. RESULTS Serum-calcium and PTH-levels normalized after surgery and did not deteriorate by observation. BMD Z-scores were normal at inclusion in the lumbar spine (LS) and femoral neck (FN). For LS, BMD Z-scores were stable for 5 years with observation, but decreased in FN (P < .02). After surgery, BMD Z-scores increased significantly in both compartments (P < .02 for both), with a highly significant treatment effect of surgery compared to observation (P < .001). During follow-up, five new clinically unrecognized vertebral fractures were found in 5 females, all in the OBS group (P = .058). CONCLUSION Even though new vertebral fractures occurred only in the observation group, the frequency was not significantly different from the surgery group. Longer follow-up is needed before firm conclusions can be drawn about the long-term safety of observation, as opposed to surgery.

Primary hyperparathyroidism and metabolic risk factors, impact of parathyroidectomy and vitamin D supplementation, and results of a randomized double-blind study

Background Vitamin D insufficiency may increase the risk for cardio metabolic disturbances in patients with primary hyperparathyroidism (PHPT). Objective To analyze the vitamin D status and indices of the metabolic syndrome in PHPT patients and the effect of vitamin D supplementation after parathyroid adenomectomy (PTX). Design and methods Double-blinded, randomized clinical trial (ClinicalTrials.gov Identifier: NCT00982722) performed at Karolinska University Hospital, Sweden, April 2008 to November 2011. One hundred and fifty consecutive patients with PHPT (119 women) were randomized after PTX, 75 to oral treatment with calcium carbonate 1000 mg daily and 75 to calcium carbonate 1000 mg and cholecalciferol 1600 IU daily over 12 months. Changes in metabolic profile and ambulatory blood pressure (BP) were analyzed. Main outcome measures were changes in metabolic factors, BP, and body composition. Results The 25-hydroxyvitamin D (25-OH-D)-level was <50 nmol/l in 76% of the patients before PTX. After PTX, glucose, insulin, and IGF1 decreased, while the 25-OH-D and the IGF-binding protein 1 increased and remained unchanged at follow-up after study medication. One year of vitamin D supplementation resulted in lower parathyroid hormone (PTH) (40 (34–52) vs 49 (38–66) ng/l) and higher 25-OH-D (76 (65–93) vs 49 (40–62) nmol/l; P<0.05). Other laboratory parameters were stable compared with after PTX. Systolic BP decreased and total bone mineral content increased in both groups. Conclusion Except for the lowering of the PTH level, no additive effect of vitamin D supplementation was seen. However, PTX proved effective in reducing insulin resistance.

Functioning and Quality of Life in Adults with Mild-to-Moderate Osteogenesis Imperfecta

PURPOSE The aim of this study was to describe physical activity, quality of and satisfaction with life, pain, joint mobility and muscle function in adults with mild-to-moderate osteogenesis imperfecta (OI) to form the basis of improved clinical care and physical therapy treatment. METHOD A total of 40 men and women aged between 21 and 71 years were identified and a prospective, cross-sectional study was performed on 29 (18 women) included participants. The participants had to be able to walk and to have a diagnosis of mild-to-moderate OI. Self-administered questionnaires and clinical examinations were used. RESULTS Difficulties were found in all domains of the International Classification of Functioning, Activity and Health. Pain was reported in 25 of 29 participants and scoliosis was found in 23 participants. Difficulty to run was estimated in 18 participants. A total of 19 of 27 participants reported reaching the recommendations of 30 min of moderate-intensity activity preferably every day. Life satisfaction was high even though health-related quality of life, assessed with the Short Form 36, was significantly lower than the Swedish norm. CONCLUSION Impairments and activity limitations involved pain, scoliosis, contractures as well as trouble with running, heavy lifting, heavy work and sports. This study show that individuals with mild-to-moderate OI perceive themselves as having decreased health-related quality of life and this seems to depend on decreased physical functioning. Despite that, as a group, they estimated high life satisfaction and 19 participants reported adhering to the general recommendation of 30 min of moderate-intensity activity preferably every day.

Associations between amino acids and bone mineral density in men with idiopathic osteoporosis

Idiopathic osteoporosis in middle-aged men is characterized by low-level bone formation. Inhibited anabolism may be involved in the pathogenesis of the disease and amino acids may be of importance. In the present study fasting amino acid profiles in plasma and erythrocytes were determined in 22 male idiopathic osteoporosis (MIO) patients and in 20 age-matched healthy men and associated with bone mineral density, bone histomorphometry and hormones. The osteoporotic patients had normal plasma essential amino acids but increased non-essential amino acids (p=0.001), particularly glutamine and glycine. The ratio essential/non-essential amino acids, an index of protein nutritional status, was decreased in the MIO patients (0.59 (0.04) μmol/l, mean (SD)), compared to controls (0.66 (0.05), p=0.001). In the MIO patients, the ratio essential/non-essential plasma amino acids (r=0.60, p=0.003) was positively correlated with lumbar spine bone mineral density. The erythrocyte amino acids represent a large proportion of the free amino acids in blood. A novel finding was the lower levels of erythrocyte tryptophan in MIO (12 (2) μmol/l) compared to controls (16 (3), p=0.001) and decreased erythrocyte/plasma ratio (0.28 (0.07) vs. 0.33, (0.06), p<0.01), suggesting an altered amino acid transport of tryptophan between plasma and erythrocytes. In the combined group of MIO and control men (n=42), bone mineral density was positively correlated with erythrocyte tryptophan in both the lumbar spine (r=0.45, p=0.003) and femoral neck (r=0.56, p<0.001). The bone histomorphometric variables wall thickness, trabecular thickness and mineral apposition rate were all positively associated with erythrocyte tryptophan levels in the MIO patients. In the combined group of MIO and controls, a multiple regression analysis showed that erythrocyte tryptophan could explain 22% of the variation of lumbar spine and 30% of the variation in femoral neck bone mineral density. We conclude that men with idiopathic osteoporosis have changes in free amino acid profiles which indicate their altered utilization. The correlations between tryptophan and bone mineral density and bone histomorphometry suggest a link between tryptophan and osteoblast function which may be important for bone health.

Vitamin D supplementation after parathyroidectomy: effect on bone mineral density-a randomized double-blind study.

Patients with primary hyperparathyroidism (PHPT) have higher bone turnover, lower bone mineral density (BMD), and an increased risk of fractures. They also have a high incidence of low vitamin D levels (25‐OH‐vitamin D <50 nmol/L) that could worsen the negative effect on the bone. In this double‐blinded clinical trial, 150 patients with PHPT were randomized, after successful parathyroidectomy (PTX), to 1‐year daily treatment with either cholecalciferol 1600 IU and calcium carbonate 1000 mg (D +) or calcium carbonate alone (D–). BMD was measured in the lumbar spine, femoral neck, total hip, distal and 33% radius using dual‐energy X‐ray absorptiometry (DXA) before surgery and after 1 year of study medication. Median age was 60 (range 30–80) years and there were 119 (79%) women and 31 (21%) men; 76% had 25‐OH‐D <50 nmol/L before PTX and 50% had persistent elevated parathyroid hormone (PTH) 6 weeks after PTX. A similar increase in BMD in the lumbar spine, femoral neck, and total hip was observed in both groups (D + : 3.6%, 3.2%, and 2.7%, p < 0.001, respectively; and D–: 3.0%, 2.3%, and 2.1%, respectively, p < 0.001). Patients with vitamin D supplementation also increased their BMD in distal radius (median 2.0%; interquartile range, −1.7% to 5.4%; p = 0.013). The changes in BMD, especially in the hips, were correlated to the baseline concentrations of PTH, ionized calcium, and bone markers (p < 0.001). A benefit from vitamin D substitution was observed among patients with a persistent postoperative PTH elevation, who also improved their BMD at 33% radius and radius ultradistal (p < 0.05). In conclusion, except for a minor improvement of radius BMD, our data show no beneficial effect on BMD or bone turnover markers of vitamin D supplementation after PTX. Preoperative PTH seems to have the strongest association with improvement in BMD.

Effect of surgery vs observation: skeletal 5-year outcomes in a randomized trial of patients with primary HPT (the SIPH study)†

Mild primary hyperparathyroidism (PHPT) is known to affect the skeleton, even though patients usually are asymptomatic. Treatment strategies have been widely discussed. However, long‐term randomized studies comparing parathyroidectomy to observation are lacking. The objective was to study the effect of parathyroidectomy (PTX) compared with observation (OBS) on bone mineral density (BMD) in g/cm2 and T‐scores and on biochemical markers of bone turnover (P1NP and CTX‐1) in a prospective randomized controlled study of patients with mild PHPT after 5 years of follow‐up. Of 191 patients with mild PHPT randomized to either PTX or OBS, 145 patients remained for analysis after 5 years (110 with validated DXA scans). A significant decrease in P1NP (p < 0.001) and CTX‐1 (p < 0.001) was found in the PTX group only. A significant positive treatment effect of surgery compared with observation on BMD (g/cm2) was found for the lumbar spine (LS) (p = 0.011), the femoral neck (FN) (p < 0.001), the ultradistal radius (UDR) (p = 0.042), and for the total body (TB) (p < 0.001) but not for the radius 33% (Rad33), where BMD decreased significantly also in the PTX group (p = 0.012). However, compared with baseline values, there was no significant BMD increase in the PTX group, except for the lumbar spine. In the OBS group, there was a significant decrease in BMD (g/cm2) for all compartments (FN, p < 0.001; Rad33, p = 0.001; UDR, p = 0.006; TB, p < 0.001) with the exception of the LS, where BMD was stable. In conclusion, parathyroidectomy improves BMD and observation leads to a small but statistically significant decrease in BMD after 5 years. Thus, bone health appears to be a clinical concern with long‐term observation in patients with mild PHPT.

FGF23, metabolic risk factors, and blood pressure in patients with primary hyperparathyroidism undergoing parathyroid adenomectomy.

BACKGROUND Fibroblast growth factor-23 (FGF23), a regulator of secretion of parathyroid hormone (PTH), is implicated in the development of cardiovascular disease. The role of FGF23 in primary hyperparathyroidism (pHPT) is unclear. METHODS A total of 150 consecutive patients with pHPT were examined with ambulatory blood pressure monitoring ((24h)ABP) before parathyroid adenomectomy (PTX). Blood samples were collected 6 ± 2 weeks before and 6 ± 2 weeks after PTX. RESULTS Plasma FGF23 levels decreased after PTX from a median of 45.2 pg/mL (interquartile range 37.6-54.8) to 36.8 pg/mL (26.7-48.7); P < .001. This postoperative decrease correlated with the decrease in ionized calcium (r = 0.24; P < .01). Greater FGF23 concentrations at baseline were associated with a greater weight of the adenoma and PTH levels, as well as with body mass index, triglycerides, and insulin levels and greater postoperative decreases in FGF23, ionized calcium, insulin growth-like factor 1, and insulin. FGF23 and PTH both correlated with greater blood pressures on (24h)ABP, especially at nighttime (r = 0.31 and r = 0.28; P ≤ .01), whereas after multivariate adjustment, only PTH remained independently associated with (24)ABP. CONCLUSION Circulating FGF23 is increased in pHPT and is associated independently with the metabolic risk profile. The long-term benefit of decreasing FGF23 in pHPT after PTX remains to be established.

Primary hyperparathyroidism, hypercalciuria, and bone recovery after parathyroidectomy

Background. In primary hyperparathyroidism, successful parathyroidectomy leads to improved bone mineral density in the majority of cases. Our aim was to further explore the relationship between hypercalciuria, kidney function, and bone recovery after parathyroidectomy. Methods. Bone mineral density, estimated glomerular filtration rate, and 24‐hour urinary calcium were analyzed before and one year after parathyroidectomy in a cohort of 150 primary hyperparathyroidism patients (119 women; median age 60 [range 30–80] years) taking part in a clinical trial. The patients were randomized to 1‐year daily treatment with either cholecalciferol 1,600 IU and calcium carbonate 1,000 mg or calcium carbonate alone. Results. Baseline 24‐hour urinary calcium correlated directly with s‐calcium, parathyroid hormone, 25‐OH‐D, the bone markers beta C‐terminal telopeptide of type 1 collagen and procollagen type 1 amino‐terminal propeptide, and estimated glomerular filtration rate (r = 0.19–0.30; P < .05) and inversely with age (r = −0.25; P = .004); 24‐hour urinary calcium decreased and bone mineral density in lumbar spine and hip increased similarly in the 2 groups. Baseline 24‐hour urinary calcium in the highest quartile (>10 mmol/d) was associated with greater increases in all locations. In a multivariable model adjusting for age, sex, smoking, diabetes, body mass index, estimated glomerular filtration rate, baseline bone mineral density, and vitamin D group, the increase in total hip bone mineral density remained independently associated with baseline 24‐hour urinary calcium in the highest quartile (>10 mmol/d) and with plasma parathyroid hormone. Patients with persistent increases in 24‐hour urinary calcium at follow‐up (14%) had similar bone mineral density improvement. Conclusion. Overall, 24‐hour urinary calcium > 10 mmol/d was an independent determinant of improvement in bone mineral density and should be taken into account when considering parathyroidectomy.