title: Serum calcium and survival in a large health screening program.
abstract: There is evidence that hyperparathyroidism is associated with increased morbidity and mortality. It is not known, however, whether elevated serum calcium (S-Ca) by itself is associated with those risks. We, therefore, examined mortality rate in relation to a single S-Ca value obtained at screening of a large population (n = 33,346) during a mean follow-up period of 10.8 yr. A survival analysis was performed, comparing groups with S-Ca values above different defined limits with those below these limits, adjusting for age and date of screening. We found that men less than 50 yr of age at screening (n = 21,131) with S-Ca greater than 2.45 mmol/L exhibited a 20% increased mortality rate compared with those with lower S-Ca values (odds ratio = 1.2; P < 0.005), whereas those with S-Ca greater than 2.60 mmol/L had a doubled rate (odds ratio = 2.0; P < 0.0002). Men less than 50 yr of age with S-Ca levels between 2.51-2.55 mmol/L exhibited a 50% increased risk of death from all causes compared with those with S-Ca between 2.31-2.45 (P < 0.0001). The excess mortality in those with S-Ca above 2.5 mmol/L was largely attributable to cardiovascular diseases (58%), although a significant excess mortality was also evident for malignant disorders (28%). In contrast, the risk of obtaining a diagnosis of malignant disease was not found to increase with rising S-Ca levels. These results indicate that the risk of premature death in men less than 50 yr of age increases with rising S-Ca, even within the normal range, and this increase may be largely due to cardiovascular diseases.
authors.affiliation: Department of Surgery, Malmo University Hospital, Lund University, Sweden.
authors.forename: B G
authors.initials: BG
authors.lastname: Leifsson
authors.forename: B
authors.initials: B
authors.lastname: Ahrén
mesh_terms: D000328:Adult; D000367:Age Factors; D002118:Calcium / Q000097:blood*; D002318:Cardiovascular Diseases / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009026:Mortality; D009369:Neoplasms / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D016019:Survival Analysis
chemical_list: D002118:Calcium