Low Parathyroid Hormone Groups Research Articles

Diagnostic Value of Four-Dimensional Dynamic Computed Tomography for Primary Hyperparathyroidism in Patients with Low Baseline Parathyroid Hormone Levels.

Low baseline levels of parathyroid hormone (PTH) are associated with a higher rate of multiglandular disease, lower localization rates of preoperative imaging modalities, and a higher rate of unsuccessful minimally invasive parathyroidectomies. The objective of this study is to assess the diagnostic value of four-dimensional dynamic computed tomography (4D-CT) in localizing primary hyperparathyroidism (pHPT) in patients with low baseline PTH levels, compared to patients with high baseline PTH levels. Patients with pHPT who received a 4D-CT scan as part of their standard diagnostic evaluation were divided into two groups based on the following criteria: (1) preoperative PTH levels less than 100 pg/mL and (2) patients with preoperative PTH levels greater than 100 pg/mL. All patients underwent parathyroidectomy based on 4D-CT findings, with intraoperative parathyroid hormone monitoring. The lesion-based sensitivity of 4D-CT was 88% in patients with low baseline PTH levels and 94.7% in patients with high baseline PTH levels (p = 0.33). However, the success rate of image-guided resection based on 4D-CT findings was 71.4% in the low baseline PTH group compared to 90.6% in the high baseline PTH group (p = 0.06). Our study demonstrated that 4D-CT has a high lesion-based sensitivity in patients with pHPT and low baseline PTH levels but led to a relatively low rate of successful image-guided resection in patients with low baseline PTH levels. Therefore, it is important to exercise increased caution during 4D-CT-guided surgical exploration of patients with low baseline PTH levels to ensure successful surgical resection of all parathyroid lesions.

Low Parathyroid Hormone Versus Secondary Hyperparathyroidism and Survival in Patients Undergoing Hemodialysis: A Propensity-Matched Analysis.

IntroductionLow serum parathyroid hormone (PTH) and secondary hyperparathyroidism (SHPT) are very common in patients undergoing hemodialysis. However, it remains unclear which of these has a lower mortality.ObjectiveIn this study, we compared outcomes between hemodialysis patients with low PTH and those with SHPT.MethodsThis was a multi-center, retrospective, matched cohort study. Median intact PTH (iPTH) was used as the cutoff for allocating participants to low PTH (iPTH<100 pg/mL) and SHPT groups (iPTH ≥600 pg/mL). Sex, diabetes, age, and dialysis vintage were matched between the groups. The primary outcome was all-cause death at 72 months.ResultsThe study cohort comprised 2282 patients (1166 in each study group). Prior to matching, the primary outcome occurred in 429/1166 patients (36.79%) in the low PTH group and in 284/1116 (25.45%) in the SHPT group. There were no significant differences in all-cause death between the groups according to multivariable Cox regression (P=0.423). The hazard ratio for low PTH versus SHPT was 1.08 (95% confidence interval, 0.90–1.30). Propensity matching created 619 pairs of patients. Baseline characteristics, including age, sex, diabetes, and dialysis vintage were comparable between the groups. The primary outcome occurred in 195/619 patients (31.50%) in the low PTH group and in 193/619 (31.18%) in the SHPT group. There were no significant differences in all-cause death between the groups according to multivariable Cox regression (P=0.43). The adjusted hazard ratio for low PTH versus SHPT was 1.10 (95% confidence interval, 0.87–1.39).ConclusionsHemodialysis patients with low PTH have similar all-cause death rates to the rates for those with SHPT.

Association of Serum Parathyroid Hormone Levels With All-Cause and Cause-Specific Mortality Among U.S. Adults

ObjectiveTo examine whether parathyroid hormone (PTH) is associated with mortality among U.S. adults. MethodsThis study included 8286 U.S. adults aged ≥20 years with a measurement of serum intact PTH from the National Health and Nutrition Examination Survey 2003-2006 linked to national mortality data through 2015. Multivariable Cox proportional hazard regression models were employed to estimate the adjusted hazard ratio (aHR) of all-cause and cause-specific (cardiovascular and cancer) mortality according to intact PTH levels (low or low-normal, <38; middle-normal, 38-56; high-normal, 57-74; high, >74 pg/mL). We also stratified the analyses by serum albumin-adjusted calcium and 25-hydroxy vitamin D (25OHD) levels. ResultsDuring a median follow-up of 10.1 years, the mean age was 49 years, and 48% were men. After adjusting for potential confounders, both the high-normal and high PTH groups showed higher risks of all-cause mortality than the low or low-normal PTH group (high-normal PTH, aHR, 1.28; 95% confidence interval [CI], 1.10-1.48; high PTH, aHR, 1.42; 95% CI, 1.19-1.69]. When stratified by calcium and 25OHD levels, the association between high PTH and mortality was also found among participants with albumin-adjusted calcium levels of ≥9.6 mg/dL (aHR, 1.53; 95% CI, 1.17-2.01) and those with 25OHD levels of ≥20 ng/mL (aHR, 1.46, 95% CI, 1.17-1.82). We found no evidence of the increased cause-specific mortality risks in the high PTH group. ConclusionHigher PTH levels were associated with an increased risk of all-cause mortality, particularly among participants with albumin-adjusted calcium levels of ≥9.6 mg/dL or 25OHD levels of ≥20 ng/mL.

Metabolic bone changes after intradialytic resistive exercise in regular haemodialysis patients

IntroductionMineral bone disease is a crucial factor that contributes to mortality and morbidity in haemodialysis patients. Intradialytic resistance exercise training can be valuable in stimulating bone formation. The aim of this study was to evaluate the metabolic bone changes after intradialytic resistive exercise training in regular haemodialysis patients.MethodsThe study involved 60 patients on regular haemodialysis, aged 20–60 years. The patients were divided into 2 groups: a high parathyroid hormone group (parathyroid hormone over 800 pg/ml) and a low parathyroid hormone group (parathyroid hormone below 200 pg/ml), both groups randomly assigned into study and control groups. They received intradialytic resistive exercise 3 times per week for 3 months. Calcium, phosphorus, and parathyroid hormone were evaluated before and after the exercise period.ResultsThe training protocol proved to be effective in improving bone metabolism parameters, as there were statistically significant differences in the high parathyroid hormone exercise group. Parathyroid hormone and phosphorus decreased and calcium increased (&lt;i&gt;p&lt;/i&gt; = 0.001, &lt;i&gt;p&lt;/i&gt; = 0.012, and &lt;i&gt;p&lt;/i&gt; = 0.025, respectively). In the low parathyroid hormone exercise group, phosphorus decreased significantly (&lt;i&gt;p&lt;/i&gt; = 0.030) and calcium increased, although not significantly (&lt;i&gt;p&lt;/i&gt; = 0.111), while parathyroid hormone non-significantly increased in the exercise group (&lt;i&gt;p&lt;/i&gt; = 0.770), with a significant increase in the control group (&lt;i&gt;p&lt;/i&gt; = 0.007). These results supported the positive effects of intradialytic resistive exercise in improving bone metabolism.ConclusionsIntradialytic resistive exercise training improves bone metabolism in haemodialysis patients.

Does Baseline PTH Influence Recovery of Bone Mineral Density, Trabecular Bone Score and Bone Turnover Markers? A Prospective Study Following Curative PArathyroidectomy in Primary Hyperparathyroidism

This prospective study was carried out to assess trabecular bone score, bone mineral density (BMD), and bone biochemistry in Indian subjects with symptomatic primary hyperparathyroidism (PHPT), and to study the influence of baseline parathyroid hormone (PTH) on recovery of these parameters following curative surgery. This was a 2-year prospective study conducted at a tertiary care centre in southern India. Baseline assessment included demographic details, mode of presentation, bone mineral biochemistry, BMD, trabecular bone score (TBS), and bone turnover markers (BTMs). These parameters were reassessed at the end of the first and second years following curative parathyroid surgery. Fifty-one subjects (32 men and 19 women) with PHPT who had undergone curative parathyroidectomy were included in this study. The mean (SD) age was 44.6 (13.7) years. The TBS, BTMs, and BMD at lumbar spine and forearm were significantly worse at baseline in subjects with higher baseline PTH (≥250 pg/mL) when compared to the group with lower baseline PTH (<250 pg/mL). At the end of 2 years, the difference between high versus low PTH groups (mean ± SD) persisted only for forearm BMD (0.638±0.093 versus 0.698±0.041 g/cm2; P =.01). However, on follow-up visits in the first and second year after curative parathyroidectomy, there was no significant difference in BTMs, BMD at the femoral neck, lumbar spine, and TBS between the 2 groups stratified by baseline PTH. The BMD at the forearm remained significantly worse in individuals with high baseline PTH even at 2 years after surgery, while other parameters including TBS improved significantly from baseline. 25(OH)D = 25-hydroxyvitamin D; BMD = bone mineral density; BMI = body mass index; BTMs = Bone turnover markers; CTX = C-terminal telopeptide of type 1 collagen; DXA = dual energy X-ray absorptiometry; P1NP = N-terminal propeptide of type 1 procollagen; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; TBS = trabecular bone score.

Early persistent hyperparathyroidism post-renal transplantation as a predictor of worse graft function and mortality after transplantation.

Persistent hyperparathyroidism (pHPT) is frequently seen after transplantation contributing to post-transplant complications. We conducted a retrospective single center analysis to explore the relationship of early pHPT and long-term allograft outcome. Patients were divided into high (N=153) and low (N=252) PTH groups based on serum parathyroid hormone (PTH) level 3months post-transplant (PTH≥150 and<150pg/mL, respectively). High PTH was found to be an independent predictor for reduced kidney allograft function up to 3years post-transplant. eGFR decreased by 11.4mL/min (P<.001) and the odds of having an eGFR<60mL/min 3years post-transplant were sixfold higher (P<.01) in the high compared to the low PTH group. Subgroup analysis based on eGFR 1year post-transplant, presence of slow graft function (SGF), and transplant type revealed similar results. High PTH three months post-transplant was also independently associated with an increased risk for overall mortality and for death with a functioning graft (P<.05). pHPT three months post-renal transplantation is an independent predictor for a worse allograft function up to 3years post-transplant and a risk factor for mortality. This relationship remains statistically significant after accounting for baseline allograft function, presence of SGF and serum mineral levels abnormalities.

Hemodialysis patients with low serum parathyroid hormone levels have a poorer prognosis than those with secondary hyperparathyroidism.

Background:Low serum parathyroid hormone (PTH) level and secondary hyperparathyroidism (SHPT) are very common in hemodialysis patients. However, the outcomes of patients with low PTH level or SHPT have not been carefully compared. Therefore, in the present study, we compared the outcomes of hemodialysis patients with low PTH level or SHPT.Methods:This was a multi-center, prospective, cohort study of 647 patients. The patients were recruited between 1 September 2016 and 1 January 2017 and followed until 31 December 2018. The participants were allocated to a low PTH group [serum intact PTH (iPTH) concentration < 60 pg/ml] and an SHPT group (iPTH ⩾ 600 pg/ml) according to their mean iPTH concentration across the entire observation period, and the outcomes were compared between these groups. The primary outcome was a composite outcome, which comprised all-cause mortality, non-fatal acute myocardial infarction, non-fatal acute stroke, and acute heart failure.Results:A total of 197 hemodialysis patients were allocated to the two groups: 87 with low PTH level and 110 with SHPT; 450 patients with time-averaged iPTH concentrations of 60–600 pg/ml were excluded. Kaplan–Meier analysis of the composite endpoint revealed a significant difference between participants with low PTH level and those with SHPT (p = 0.002). Cox multiple regression showed that participants with low PTH level had a higher incidence of the composite endpoint than those with SHPT (relative risk: 1.337, 95% confidence interval: 1.059–1.688).Conclusion:Hemodialysis patients with low PTH level had a higher incidence of mortality and non-fatal cardiovascular events than those with SHPT, irrespective of whether the participants were age-matched.

Association of low serum parathyroid hormone with protein-energy wasting in maintenance hemodialysis patients

Objective: To examine the relationship between low serum parathyroid hormone (PTH) and protein-energy wasting (PEW) in patients who underwent maintenance hemodialysis (MHD) treatment. Methods: A cross-sectional study was conducted in MHD patients between June 2015 and August 2017 in 11 MHD centers from Guizhou province. Body composition and physical parameters were measured, clinical data and other related laboratory values were collected according to the medical record system. Participants were assigned to low serum PTH group (PTH<150 ng/L), target PTH group (150 ng/L≤ PTH ≤300 ng/L) and high serum PTH group (PTH>300 ng/L). Multivariate logistic regression analysis was used to analyze the relationship between low serum PTH and risk of PEW, which was diagnosed according to the diagnostic criteria recommened by the International Society of Renal Nutrition and Metabolism (ISRNM). Results: A total of 873 MHD patients (488 males and 385 females) were included in the final analysis, with a mean age of 55.0 (44.0, 67.0) years and a mean hemodialysis duration of 31.0(17.0, 54.0) months. In unadjusted model, low serum PTH group was associated with PEW (OR=2.12, 95% CI: 1.26-3.54, P=0.004), when compared with high serum PTH group. After adjustment for age and sex, low serum PTH group was still significantly associated with PEW (OR=2.09, 95% CI: 1.23-3.52, P=0.006). Further adjustment for diabetes and hypertension, the correlation between low serum PTH group and PEW was still significant (OR=2.02, 95% CI: 1.04-3.90, P=0.037). However, the correlation was not observed in target PTH group and high serum PTH group. Conclusion: Low serum PTH was associated with risk of PEW, regardless of age, sex, history of diabetes and hypertension, and thus it might be a promising indicator of PEW in MHD patients.

Low parathyroid hormone levels after parathyroidectomy reduce cardiovascular mortality in chronic hemodialysis patients.

The aim of the study is to elucidate whether parathyroid hormone (PTH) levels after parathyroidectomy affect the prognosis of patients with secondary hyperparathyroidism. Two hundred and ninety-five patients, who underwent PTx without autotransplantation from July 1998 to December 2011, were divided into the low (n=148) and high (n=147) PTH groups, using the median value of each mean value of intact PTH after surgery (16.6pg/mL). After observation for 5.00years, we evaluated demographic factors, influences of postoperative mineral metabolism, magnitude of uremia, and vitamin D receptor activators on their prognosis, with the multivariate Cox proportional hazard model. While overall survival rates in the high and low PTH groups were 54.9 and 74.2%, respectively (P=0.1500), cardiovascular survival rates were 71.6 and 94.4%, respectively (P=0.0256). The hazard ratio for cardiovascular mortality in the high PTH group (≥16.6pg/mL) was 3.132 (P=0.0470), and those in groups with the median age more than 59years and with cardiovascular disease were 2.654 (P=0.0589) and 3.377 (P=0.0317), respectively. The intact PTH level 6days after surgery and the mean postoperative intact PTH value showed a strong correlation (Spearman ρ=0.9007, P<0.0001, y=0.4725x+30.395, R 2=0.51798). The present study suggests that maintaining low PTH levels after parathyroidectomy reduces cardiovascular mortality and improves the prognosis. Total parathyroidectomy (more than 4 glands) without autotransplantation seems to be one of the treatment options for managing severe secondary hyperparathyroidism.

Anti-sclerostin antibody treatment in a rat model of progressive renal osteodystrophy.

Chronic kidney disease (CKD) is associated with abnormalities in bone quantity and quality, leading to increased fractures. Recent studies suggest abnormalities of Wnt signaling in animal models of CKD and elevated sclerostin levels in patients with CKD. The goal of this study was to evaluate the effectiveness of anti-sclerostin antibody treatment in an animal model of progressive CKD with low and high parathyroid hormone (PTH) levels. Cy/+ male rats (CKD) were treated without or with calcium in the drinking water at 25 weeks of age to stratify the animals into high PTH and low PTH groups, respectively, by 30 weeks. Animals were then treated with anti-sclerostin antibody at 100 mg/kg i.v. weekly for 5 doses, a single 20-µg/kg subcutaneous dose of zoledronic acid, or no treatment, and were then euthanized at 35 weeks. As a positive control, the efficacy of anti-sclerostin antibody treatment was also evaluated in normal littermates. The results demonstrated that the CKD animals with high PTH had lower calcium, higher phosphorus, and lower FGF23 compared to the CKD animals with low PTH. Treatment with anti-sclerostin antibody had no effect on any of the biochemistries, whereas zoledronic acid lowered dkk-1 levels. The anti-sclerostin antibody increased trabecular bone volume/total volume (BV/TV) and trabecular mineralization surface in animals with low PTH, but not in animals with high PTH. Neither anti-sclerostin antibody nor zoledronic acid improved biomechanical properties in the animals. Cortical porosity was severe in high-PTH animals and was unaffected by either treatment. In contrast, in normal animals treated with anti-sclerostin antibody, there was an improvement in bone volume, cortical geometry, and biomechanical properties. In summary, this is the first study to test the efficacy of anti-sclerostin antibody treatment on animals with advanced CKD. We found efficacy in improving bone properties only when the PTH levels were low.

High serum parathyroid hormone and calcium are risk factors for hypertension in Japanese patients.

Excess parathyroid hormone (PTH), known as primary hyperparathyroidism (pHPT), results in hypercalcemia and bone loss. Recent studies have shown that PTH is associated with the occurrence of hypertension in Western countries; however, controversy remains regarding high serum levels of PTH and calcium as risk factors for hypertension in Japanese patients. We retrospectively enrolled 114 consecutive Japanese patients who visited our hospital for examination and treatment of hypercalcemia and/or hypertension with serum calcium levels ≥ 9.8 mg/dL. To estimate the prevalence of hypertension, the patients were categorized according to calcium levels into hypercalcemic (10.2-13.4 mg/dL) and normocalcemic (9.8-10.1 mg/dL) groups, which were further categorized into high PTH (50-440 pg/mL) and low PTH (8-49 pg/mL) groups. The prevalence of hypertension was higher in patients with hypercalcemia than in patients with normocalcemia in both the high and low PTH groups. The prevalence of hypertension was higher in patients with high serum PTH levels than in patients with low serum PTH levels in both the hypercalcemic and normocalcemic groups. Logistic multiple regression analysis determined that serum calcium (P < 0.05) and PTH (P < 0.01) levels were positive contributors to hypertension. In conclusion, high serum levels of PTH and calcium are risk factors for hypertension in Japanese patients.

The impact of lifestyle factors on serum 25-hydroxyvitamin D levels: a cross-sectional study in Japanese women aged 19–25 years

Insufficient levels of serum 25-hydroxyvitamin D [25(OH)D] lead to low bone mineral density (BMD) by increasing serum levels of intact parathyroid hormone (PTH), and are associated with a high mortality rate. Therefore, the 25(OH)D level is used as an indicator of frailty in older persons. To obtain higher serum 25(OH)D levels, management of lifestyle habits and nutrient intake is important beginning in a person's younger years. This study evaluated the degree of association between serum 25(OH)D concentrations and lifestyle factors in young Japanese women. A cohort study was conducted from December 2003, and the survey was finished by February 2004. The subjects were 274 Japanese women aged 19-25 years old. The parameters evaluated in these subjects included: (1) serum concentrations of 25(OH)D, intact PTH, calcium, and phosphorus; (2) BMD in the lumbar spine and hip; and (3) lifestyle factors (nutrient intake, physical activity, and duration of sunlight exposure). The serum 25(OH)D level was negatively associated with the intact PTH level (Spearman; r = -0.17, P = 0.006). The BMD was significantly higher in the high 25(OH)D and low intact PTH group than the other group (P < 0.05). The serum 25(OH)D level was significantly correlated with daily intake of dietary vitamin D (r = 0.20, P = 0.001), the mean number of steps taken per day (r = 0.16, P = 0.010) and the mean time spent in sedentary activity (r = -0.14, P = 0.018) among the lifestyle factors evaluated. Multiple regression analysis showed the degree of association between lifestyle factors and serum 25(OH)D to be small (R (2) = 0.084). Daily intake of dietary vitamin D and daily walking may be useful for increasing the serum 25(OH)D level in young Japanese women.

The whole-PTH/intact-PTH ratio is a useful predictor of severity of secondary hyperparathyroidism.

Background. The newer parathyroid hormone (PTH) assay, whole-PTH, uses an antibody that binds the region harbouring the first amino acid, making it specific for the complete molecule, 1–84-PTH. Especially among dialysis patients, it has been reported that the level of whole-PTH can be calculated as ∼60% of their intact-PTH value. In addition, since 1–84-PTH is part of intact-PTH, the whole-PTH/intact-PTH ratio should not theoretically exceed 1. However, an abnormally high 1–84-PTH/intact-PTH ratio is reported in a few patients with parathyroid carcinoma, primary hyperparathyroidism and secondary hyperparathyroidism. In this study, we examined the correlation between the 1–84-PTH/intact-PTH ratio and the severity of hyperparathyroidism in patients on haemodialysis (HD).Patients and methods. The study population comprised 196 HD patients (males 113, females 83, age 67.4 ± 13.6 years, HD period 8.1 ± 7.3 years; mean ± SD). The whole-PTH/intact-PTH ratio was compared in patients with high PTH levels (intact-PTH ≥300 pg/ ml; high PTH group, n = 32), moderate PTH levels (intact-PTH >150–<300 pg/ml; moderate PTH group, n = 50) and low PTH levels (intact-PTH <150 pg/ml; low PTH group, n = 114). The ratio was also compared in 25 patients with at least one enlarged gland >0.5 cm3 suggesting nodular hyperplasia, as determined by power Doppler ultrasonography (hyperplasia group) with seven patients without enlarged gland (non-hyperplasia group) and six patients who had undergone total parathyroidectomy (post-PTx group).Results. The whole-PTH/intact-PTH ratio of the high PTH group (0.68 ± 0.1) was significantly higher than those of the moderate (0.61 ± 0.1, P < 0.001) and low (0.52 ± 0.1, P < 0.001) groups. Moreover, the ratio was significantly higher in the hyperplasia group (0.70 ± 0.1) than those in the non-hyperplasia group (0.59 ± 0.1, P < 0.05) and post-PTx group (0.456 ± 0.12, P < 0.001).Conclusions. The whole-PTH/intact-PTH ratio correlated with the severity of hyperparathyroidism. Our results suggest that the ratio might be a useful predictor of severity of secondary hyperparathyroidism in HD patients.

AUSTRALIAN ENDOCRINE SURGEONS GUIDELINES AES06/01. POSTOPERATIVE PARATHYROID HORMONE MEASUREMENT AND EARLY DISCHARGE AFTER TOTAL THYROIDECTOMY: ANALYSIS OF AUSTRALIAN DATA AND MANAGEMENT RECOMMENDATIONS

The risk of hypocalcaemia after thyroidectomy has traditionally mandated inpatient monitoring for signs and symptoms as well as frequent measurement of serum calcium levels. In recent years there has been much interest in the published work about the use of intact parathyroid hormone (PTH) to better predict hypocalcaemia after thyroidectomy. Although generally accurate, the use of intact parathyroid hormone in Australia has not become widespread. On behalf of the Australian Endocrine Surgeons an analysis of Australian data on the use of PTH levels to predict hypocalcaemia after thyroidectomy was carried out. The data were analysed with a view to making recommendations about the use of this test in clinical practice and the feasibility of achieving safe early discharge for patients. Four recently published or presented Australian studies on the use of early postoperative PTH levels after total or completion thyroidectomy to predict post-thyroidectomy hypocalcaemia were analysed. Patients were stratified into either normal or low PTH groups as defined by the normal ranges set by each laboratory and rates of hypocalcaemia were analysed. A total of 458 patients were examined. Seventy-six per cent of the patients had PTH in the normal range and hypocalcaemia (serum-corrected calcium cCa(2+) < 2.00 mmol/L) occurred in 17.9% of patients. Sensitivity, specificity and positive predictive values of a normal postoperative PTH level as a predictor of normocalcaemia are 92.6, 70.7 and 92.3%, respectively. Low PTH as a predictor of hypocalcaemia is poor. The overall sensitivity, specificity and positive predictive values are 70.7, 92.6 and 71.6%, respectively. Normal postoperative PTH levels accurately predict normocalcaemia after total or completion thyroidectomy. PTH levels should ideally be drawn 4 h postoperatively and patients with PTH in the normal range can be safely discharged on the first postoperative day. Use of oral calcium supplements, either as needed or routinely, will avoid mild symptoms that may develop in 7% without treatment.

The role of secondary hyperparathyroidism in left ventricular hypertrophy of patients under chronic hemodialysis

End-stage renal disease (ESRD) patients frequently develop structural cardiac abnormalities, particularly left ventricular hypertrophy (LVH). The mechanisms involved in these processes are not completely understood. In the present study, we evaluated a possible association between parathyroid hormone (PTH) levels and left ventricular mass (LVM) in patients with ESRD. Stable uremic patients on intermittent hemodialysis treatment were evaluated by standard two-dimensional echocardiography and their sera were analyzed for intact PTH. Forty-one patients (mean age 45 years, range 18 to 61 years), 61% males, who had been on hemodialysis for 3 to 186 months, were evaluated. Patients were stratified into 3 groups according to serum PTH: low levels (< 100 pg/ml; group I = 10 patients), intermediate levels (100 to 280 pg/ml; group II = 10 patients) and high levels (> 280 pg/ml; group III = 21 patients). A positive statistically significant association between LVM index and PTH was identified (r = 0.34; P = 0.03, Pearson's correlation coefficient) in the sample as a whole. In subgroup analyses, we did not observe significant associations in the low and intermediate PTH groups; nevertheless, PTH and LVM index were correlated in patients with high PTH levels (r = 0.62; P = 0.003). LVM index was also inversely associated with hemoglobin (r = -0.34; P = 0.03). In multivariate analysis, after adjustment for age, hemoglobin, body mass index, and blood pressure, the only independent predictor of LVM index was PTH level. Therefore, PTH is an independent predictor of LVH in patients undergoing chronic hemodialysis. Secondary hyperparathyroidism may contribute to the elevated cardiovascular morbidity associated with LVH in ESRD.