Serum calcium levels are associated with novel cardiometabolic risk factors in the population-based CoLaus study

Association of Total Calcium With Serum Uric Acid Levels Among United States Adolescents Aged 12-19 Years: A Cross-Sectional Study

Aims

Evidence of a link between total calcium (CA) and serum uric acid (SUA) is absent in adolescents. Thus, this study aimed to determine the relationship between total CA levels and SUA levels in United States adolescents.

Methods

A cross-sectional study analyzed a sample composed of 8,309 United States adolescents aged 12–19 years from the National Health and Nutrition Examination Survey database (1999–2006 survey cycle). Multivariable linear regression analyses and multivariable logistic regression analyses were used to assess the correlation of total CA with SUA levels and hyperuricemia. Furthermore, the dose-response relationship of total CA and SUA levels was analyzed using smooth curve fitting (penalized spline method).

Results

According to multivariable linear regression analysis, every 1 mg/dL increase in total CA level is associated with a 0.33 mg/dL (β = 0.33, 95% CI: 0.27–0.40, p < 0.001) increase in SUA. Multivariable logistic regression analyses showed that every 0.1 mg/dL increase in total CA level is linked with an 8% increased risk of hyperuricemia (OR = 1.08, 95% CI: 1.06–1.10, p < 0.001). The analyses of smooth curve fitting revealed that total CA levels were linearly correlated with SUA levels (P_{non–linearity} = 0.152). The results were highly stable in all subgroups. The interaction analysis results presented that race/ethnicity had an interactive role in associating total CA with SUA levels.

Conclusions

In United States adolescents, total CA levels were linearly and positively correlated with SUA levels.

The Relationship Between Menopause and Metabolic Syndrome: Experimental and Bioinformatics Analysis

Menopausal hormonal changes have been associated with the emergence of the metabolic syndrome (MetS) and its consequences such as type 2 diabetes (T2D) and cardiovascular diseases (CVD). The common gene signature and the associated signaling pathways of MetS, T2D, CVD and menopause status have not been widely studied. We analyzed a total of 314 women aged between 35 and 75 years. The sample was divided into two groups: Group I, including women in the premenopausal period and Group II, comprising women in the post-menopausal period. The presence of MetS and its components were evaluated, as well as occurrence of T2D and CVD in both groups. We also exploited the translational bioinformatics approach to choose the common gene signatures for MetS, T2D, CVD and the menopause status. The frequency of the MetS was significantly higher in postmenopausal women than in premenopausal ones (67.1 vs. 27.2%, p < 0.001). Gene mining analysis revealed that a total of 47 genes were commonly associated with MetS, T2D, CVD and the menopausal changes. The gene enrichment analysis showed that these genes were markedly enriched in biological processes, including positive regulation of binding, positive regulation of leukocyte cell-cell adhesion, regulation of lipid localization. Furthermore, P53 signaling pathway, prolactin signaling pathway, parathyroid hormone synthesis, secretion and action were the top enriched pathways. Additionally, network analysis revealed TGFB1, SPP1, MMP2, MMP9, CCL2, IGF1, EGFR, ICAM1, TNF and IL6 as important hub genes with significant interacting partners. These hub genes identified in our study may play key role in menopausal changes and influence the risks of MetS, T2D and CVD.

Dose-response relationship between higher serum calcium level and higher prevalence of hyperuricemia: A cross-sectional study

The aim of the study was to examine the relationship between serum calcium (Ca) levels and the prevalence of hyperuricemia (HU).The data included in this analysis were extracted from a population-based study conducted at the Xiangya Hospital Health Management Centre. Serum Ca levels were measured using the Arsenazo III method. HU was defined as the uric acid ≥416 μmol/L for male subjects, and ≥360 μmol/L for female subjects. The association between serum Ca levels and the prevalence of HU was evaluated using logistic and spline regression.The present study included a total of 6337 subjects. The overall prevalence of HU for the target population was 17.5%. Compared with the lowest quintile, the odds ratios adjusted by age, sex, body mass index, smoking, and drinking for HU were 1.51 [95% confidence interval (CI): 1.20-1.91], 1.43 (95% CI: 1.13-1.82), 2.02 (95% CI: 1.61-2.54), and 2.54 (95% CI: 2.02-3.18) for the second, third, fourth, and fifth quintiles of serum Ca levels, respectively (P for trend <.001), and a positive dose-response relationship was observed. Similar results were observed for men and women, respectively. The findings were not materially altered by the adjustment for further potential confounders.Subjects with higher serum Ca levels are subject to a higher prevalence of HU in a dose-response relationship manner.

Genotype effects of glucokinase regulator on lipid profiles and glycemic status are modified by circulating calcium levels: results from the Korean Genome and Epidemiology Study

Single nucleotide polymorphisms (SNPs) in the glucokinase regulator (GCKR) are associated with major cardiovascular risk factors (ie, lipid profile and glycemic status). Recently, GCKR was shown to be related to circulating calcium levels involved in lipid and glycemic controls. Therefore, we hypothesized that GCKR SNPs are associated with major cardiovascular risk factors in the Korean population, and the association is modified by circulating calcium levels. Epidemiological data and GCKR SNPs (rs780093T>C, rs780094 T>C, and rs1260326 T>C) were collected from a subset of Ansung-Ansan cohort in the Korean Genome and Epidemiology Study (n = 7815). Consistent with the results of previous studies, GCKR SNPs were significantly associated with decreased total cholesterol and triglyceride levels and increased glucose levels and insulin resistance. Minor C allele carriers, particularly CC homozygotes, had lower serum calcium levels than TT homozygotes for all 3 SNPs. Particularly, the effect of GCKR SNPs on total cholesterol, triglyceride, fasting glucose, and insulin resistance was apparent when serum calcium levels were in normal range (8.8-10.1 mg/dL). When serum calcium levels were high (≥10.2 mg/dL), CC homozygotes also had significantly lower triglyceride and higher fasting glucose than TT homozygotes. However, the associations were not observed when serum calcium levels were low (<8.8 mg/dL). In conclusion, GCKR SNPs are associated with lipid profiles and glycemic status in the Korean population, and the genetic effect is modified by basal circulating calcium levels, particularly in normal or high ranges. It provides important information for individualized prevention and management of cardiovascular risk associated with GCKR SNPs.

Association between Parathyroid Hormone, 25 (OH) Vitamin D, and Chronic Kidney Disease: A Population-Based Study

Identification of the accurate risk factor for CKD remains mandatory to combat the high prevalence of diseases. Growing evidence suggests the association of serum vitamin D with diverse health conditions. However, the relationship between vitamin D, intact parathyroid hormone (PTH), and calcium-phosphate metabolism and development of CKD remains controversial. We conduct this cross-sectional observational study to investigate the association between serum 25 (OH) vitamin D, intact PTH, and calcium and phosphate levels with eGFR and albuminuria, as a surrogate marker of CKD, in a community population. A total of 4080 participants were recruited. The mean age was 58.4 ± 13.3 years and 1480 (36.3%) were men. The mean eGFR was 94.1 ± 26.3 mL/min/1.73 m². The prevalence of CKD was 19.8%. Serum 25 (OH) vitamin D and log intact PTH levels were inversely correlated with eGFR but positively correlated with log albuminuria. Logistic regression analysis identified the log intact PTH as an independent factor associated with eGFR ≤ 60 mL/min/1.73 m² and proteinuria. This association was consistent when serum intact PTH was analyzed as continuous as well as categorical variables (as hyperparathyroidism). The relationship remains significant using resampling subset analysis with comparable baseline characteristics and adjustment for 25 (OH) vitamin D, calcium, and phosphate levels. This finding warranted further research to clarify the causal relationship of PTH/25 (OH) vitamin D with the risk of CKD in the general population.

Serum Calcium and the Risk of Incident Metabolic Syndrome: A 4.3-Year Retrospective Longitudinal Study

BACKGROUND

An association between serum calcium level and risk of metabolic syndrome (MetS) has been suggested in cross-sectional studies. This study aimed to evaluate the association between baseline serum calcium level and risk of incident MetS in a longitudinal study.

METHODS

We conducted a retrospective longitudinal study of 12,706 participants without MetS who participated in a health screening program, had normal range serum calcium level at baseline (mean age, 51 years), and were followed up for 4.3 years (18,925 person-years). The risk of developing MetS was analyzed according to the baseline serum calcium levels.

RESULTS

A total of 3,448 incident cases (27.1%) of MetS developed during the follow-up period. The hazard ratio (HR) for incident MetS did not increase with increasing tertile of serum calcium level in an age- and sex-matched model (P for trend=0.915). The HRs (95% confidence interval [CI]) for incident MetS comparing the second and the third tertiles to the first tertile of baseline serum calcium level were 0.91 (95% CI, 0.84 to 0.99) and 0.85 (95% CI, 0.78 to 0.92) in a fully adjusted model, respectively (P for trend=0.001). A decreased risk of incident MetS in higher tertiles of serum calcium level was observed in subjects with central obesity and/or a metabolically unhealthy state at baseline.

CONCLUSION

There was no positive correlation between baseline serum calcium levels and incident risk of MetS in this longitudinal study. There was an association between higher serum calcium levels and decreased incident MetS in individuals with central obesity or two components of MetS at baseline.

The association between serum uric acid and metabolic syndrome among adolescents in northeast China

PURPOSE

Data about the association between serum uric acid and metabolic syndrome in healthy adolescents are sparse. This study examined this association and determined the optimal cutoffs for serum uric acid to predict metabolic syndrome among healthy adolescents.

METHODS

During 2010-2011, we conducted a cross-sectional study of 927 adolescents (53.0% boys) aged 11-16 years from junior and senior high schools in northeast China. All participants received a physical examination and gave venous blood samples.

RESULTS

Serum uric acid was positively associated with abdominal obesity, dyslipidemia and hypertension in boys and with abdominal obesity and dyslipidemia in girls. For those with hyperurecemia, the odds ratios (95% CI) for metabolic syndrome were 7.67 (95% CI, 2.58~22.78) for boys and 4.77 (95% CI, 1.01~22.60) for girls. SUA was a better predictor of metabolic syndrome than fasting glucose, though not as good as waist circumference.

CONCLUSIONS

Among adolescents in China, serum uric acid level may be a useful predictor of metabolic syndrome.

Plasma calcium as a predictor of cardiovascular disease in a community-based cohort

OBJECTIVE

Primary hyperparathyroidism and calcium supplementation have been linked to cardiovascular outcomes. The study objective was to examine plasma calcium as a predictor of cardiovascular disease in the general population, as results from previous cohort studies are conflicting.

DESIGN, PARTICIPANTS AND MEASUREMENTS

Plasma calcium was measured in 4003 participants (aged 25-84 years) in the 1994/1995 Busselton Health Survey. Using a Cox proportional hazards model, we examined albumin-corrected calcium as a predictor of total mortality, cardiovascular mortality and cardiovascular events up to the end of 2010.

RESULTS

At baseline, there were significant positive relationships between plasma calcium and each of body mass index, systolic and diastolic blood pressure, glucose and total cholesterol. During the follow-up period, 666 participants died (278 from cardiovascular disease) and 652 had incident cardiovascular events. After adjustment for age and sex, each additional 0.1 mm of albumin-corrected calcium at baseline was associated with a hazard ratio (HR) of 1.09 [95% confidence interval (CI) 0.99, 1.20; P = 0.062] for total mortality, 1.06 (95% CI 0.92, 1.23; P = 0.41) for cardiovascular mortality and 1.13 (95% CI 1.03, 1.24; P = 0.012) for cardiovascular events. These associations were attenuated by further adjustment for standard cardiovascular risk factors with HR 1.03 (95% CI 0.94, 1.14), 0.99 (95% CI 0.86, 1.16) and 1.05 (95% CI 0.95, 1.15), respectively.

CONCLUSION

After adjustment for age and sex, plasma calcium is a predictor of cardiovascular events. This appears to be mediated by conventional cardiovascular risk factors, and calcium is not an independent predictor of cardiovascular disease.

The role of serum magnesium and calcium on the association between adiponectin levels and all-cause mortality in end-stage renal disease patients

BACKGROUND

Adiponectin (ADPN) is the most abundant adipocyte-specific cytokine that plays an important role in energy homeostasis by regulating lipid and glucose metabolism. Studies of the impact of ADPN on clinical outcomes have yielded contradictory results so far. Here, we examined the association of ADPN with serum magnesium (s-Mg) and calcium (s-Ca) levels and explored the possibility whether these two factors could modify the relationship between ADPN and all-cause mortality in patients with end-stage renal disease.

METHODOLOGY/PRINCIPAL FINDINGS

After baseline assessment, 47 hemodialysis and 27 peritoneal dialysis patients were followed- up for a median period of 50 months. S-Mg and s-Ca levels emerged as positive and negative predictors of ADPN levels, respectively. During the follow-up period 18 deaths occurred. There was a significant 4% increased risk for all-cause mortality for each 1-µg/ml increment of ADPN (crude HR, 1.04; 95% CI, 1.01-1.07), even after adjustment for s-Mg and s-Ca levels, dialysis mode, age, albumin and C-reactive protein. Cox analysis stratified by s-Mg levels (below and above the median value of 2.45 mg/dl) and s-Ca levels (below and above the median value of 9.3 mg/dl), revealed ADPN as an independent predictor of total mortality only in the low s-Mg and high s-Ca groups. Furthermore, low s-Mg and high s-Ca levels were independently associated with malnutrition, inflammation, arterial stiffening and risk of death.

CONCLUSIONS/SIGNIFICANCE

The predictive value of ADPN in all-cause mortality in end-stage renal disease patients appears to be critically dependent on s-Mg and s-Ca levels. Conversely, s-Mg and s-Ca may impact on clinical outcomes by directly modifying the ADPN's bioactivity.