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Objective: The relationship between serum levels of calcium, parathyroid hormone (PTH) and risk of venous thromboembolism (VTE) has not been addressed in population-based cohorts. We investigated the associations between serum levels of calcium and PTH, with future risk of VTE in a general adult population. Design: Population-based cohort. Methods: A total of 27 712 subjects (25–87 years) who participated in Tromsø 4 (1994–1995) and Tromsø 5 (2001–2002) surveys were included in the study, and total calcium and PTH were measured in 27 685 and 8547 subjects respectively. Incident VTE was recorded through December 31, 2012. Cox-regression models with calcium and PTH as time-varying exposures were used to calculate hazard ratios (HR) of VTE by quartiles of calcium and PTH. Quartiles of calcium and PTH were also combined to assess the effect of discordants of both PTH and calcium (e.g. highest and lowest quartiles of both calcium and PTH) on VTE risk using the middle two quartiles as reference. Results: There were 712 VTEs during 15.0 years of median follow-up. Serum levels of calcium and PTH were not associated with risk of VTE. However, subjects with discordant high serum levels of both calcium and PTH (calcium ≥2.45 mmol/L and PTH ≥4.0 pmol/L) had increased risk of VTE compared to those in subjects with normal calcium and PTH (multivariable HR: 1.78, 95% CI: 1.12–2.84). Conclusions: Serum levels of calcium and PTH separately were not associated with future risk of VTE, but subjects with high levels of both calcium and PTH had increased risk of VTE compared to those in subjects with normal levels. [ABSTRACT FROM AUTHOR]

Background: Serum osteoprotegerin (OPG) is elevated in patients with chronic kidney disease (CKD) and increases with decreasing renal function. However, there are limited data regarding the association between OPG and renal function in the general population. The aim of the present study was to explore the relation between serum OPG and renal function in subjects recruited from the general population. Methods: We conducted a cross-sectional study with 6689 participants recruited from the general population in Tromsø, Norway. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equations. OPG was modelled both as a continuous and categorical variable. General linear models and linear regression with adjustment for possible confounderswere used to study the association between OPG and eGFR. Analyseswere stratified by the median age, as serum OPG and age displayed a significant interaction on eGFR. Results: In participants ≤62.2 years with normal renal function (eGFR ≥90 mL/min/1.73m2) eGFR increased by 0.35 mL/min/1.73m2 (95% CI 0.13-0.56) per 1 standard deviation (SD) increase in serum OPG after multiple adjustment. In participants older than the median age with impaired renal function (eGFR <90 mL/min/1.73m2), eGFR decreased by 1.54 (95% CI - 2.06 to - 1.01) per 1 SD increase in serum OPG. Conclusions: OPGwas associated with an increased eGFR in younger subjects with normal renal function and with a decreased eGFR in older subjects with reduced renal function. Our findings imply that the association between OPG and eGFR varies with age and renal function. [ABSTRACT FROM AUTHOR]

Objective: The relationship between thyroid function and the risk of venous thromboembolism(VTE) has not been addressed in population-based cohorts. We investigated the association between TSHlevels and the risk of VTE in a general adult population. Design: Population-based cohort study. Methods: TSHwasmeasured in 11 962 subjects aged 25-89 years who participated in Tromsø 4-6 starting in 1994-1995. Incident VTE eventswere recorded through 31st December 2010. Cox's regression models with TSH as a time-varying covariatewere used to calculate hazard ratios (HRs) of VTE by TSH categories (low TSH: <0.05 mU/l; moderately reduced TSH: 0.05-0.19 mU/l; normal TSH: 0.20-4.00 mU/l;moderately elevated TSH: 4.01-5.00 mU/l; and high TSH: >5.00 mU/l) and within the normal range of TSH, modeling TSH as a continuous variable. Results: Therewere 289 VTEs during 8.2 years of median follow-up. Subjectswith low(prevalence: 0.22%) and high (3.01%) TSH had slightly higher risk estimates for VTE than did subjects with normal TSH (multivariable HRs: 2.16, 95%CI 0.69-6.76 and 1.55, 95% CI 0.87-2.77 respectively), but the CIs were wide. Moreover, there was no association between TSH within the normal range and VTE (HR per 1 mU/l increase: 0.95, 95% CI 0.82-1.11). Conclusion: Serum levels of TSH within the normal range were not associated with a risk of VTE, whereas low and high TSH levels were rare and associatedwith amoderately higher risk of VTE. The present findings suggest that only aminor proportion of the VTE risk in the population can be attributed to thyroid dysfunction. [ABSTRACT FROM AUTHOR]