Objectives This study aimed to evaluate the potential interaction between kidney function and the non-linear association between serum calcium levels and cardiovascular disease (CVD) mortality.
Methods This study included 8927 participants enrolled in the Dong-gu Study. Albumin-corrected calcium levels were used and categorized into 6 percentile categories: <2.5th, 2.5-25.0th, 25.0-50.0th, 50.0-75.0th, 75.0-97.5th, and >97.5th. Restricted cubic spline analysis was used to examine the non-linear association between calcium levels and CVD mortality. Cox proportional hazard regression was used to estimate hazard ratios (HRs) for CVD mortality according to serum calcium categories. All survival analyses were stratified by the estimated glomerular filtration rate.
Results Over a follow-up period of 11.9±2.8 years, 1757 participants died, of whom 219 died from CVD. A U-shaped association between serum calcium and CVD mortality was found, and the association was more evident in the low kidney function group. Compared to the 25.0-50.0th percentile group for serum calcium levels, both low and high serum calcium tended to be associated with CVD mortality (<2.5th: HR, 6.23; 95% confidence interval [CI], 1.16 to 33.56; >97.5th: HR, 2.56; 95% CI, 0.76 to 8.66) in the low kidney function group. In the normal kidney function group, a similar association was found between serum calcium levels and CVD mortality (<2.5th: HR, 1.37; 95% CI, 0.58 to 3.27; >97.5th: HR, 1.65; 95% CI, 0.70 to 3.93).
Conclusions We found a non-linear association between serum calcium levels and CVD mortality, suggesting that calcium dyshomeostasis may contribute to CVD mortality, and kidney function may modify the association.
Summary
Korean summary
- 혈중 칼슘 농도와 심혈관 질환에 의한 사망은 U자형의 비선형 연관성을 보였다.
- 혈중 칼슘 농도와 심혈관 질환에 의한 사망의 비선형 연관성은 신기능이 정상인 그룹보다 신기능이 낮은 그룹에서 더 유의하게 나타났다.
To investigate the factors which affecting the cognitive impairment of the 60 or more age group, the authors surveyed for the subjects in some area of Kyungnam Province. 201 studied subjects were tested for cognitive function with mini-mental state examination(MMSE). Information on demographic characteristics and life style has been collected through direct interview. The concentration of Al and Ca of subject's drinking water, which might be related with cognition, was measured by Inductively Coupled Argon Plasma Spectrometer. The main results were summarized as follows. 1. The prevalence rate of cognitive impairment was 18.4% in male and 45.2% in female and this sexual difference was statistically significant(p=0.03). And the uneducated or illiterated showed significantly high prevalence rate of cognitive impairment(p=0.02). 2. In stratified analysis by sex and education year, we can not see significant trend indicating the neurotoxic effects of aluminum and protective effects of calcium to the cognitive function(p>0.05). 3. The correlation between the concentration of aluminum in drinking water and the MMSE score in whole subjects showed weak negative relationship(r=-0.066). But there was no statistical significance(p=0.434).
This study was carried out to clarify the effect of dietary calcium, casein, and suet on the accumulation of cadmium in mice. It was performed for 30 days, from April 11 to May 10 1988. 90 mice were divided into 4 experimental groups and control group with 6 mice each dietary group, and measured survival rate, body weight, and weight ratio of organ to body. The contents of cadmium in liver, kidney, spleen, muscle and skin with hair, and faces were analyzed by atomic absorption spectrophotometer after sacrifice by anesthesia. After 30 days, the survival rate of control group was 100%, but 66.7% in group IV(basal+Cd+Ca) with single dose of 100 microgram cadmium and with free-intake of water containing 50ppm cadmium, and group V(basal diet+Cd+suet) with free-intake of water containing 50ppm cadmium. The rate of weight gain in the case of single dose of 100 microgram cadmium was highest in group IV as 42.3% and lowest in group V as 26.0%, whereas in the cases of free intake group IV was highest as 24.0% and group II(basal diet+Cd) was lowest as 11.6%. The body weight, in the case of single dose of 100 microgram cadmium showed no increase until 5th day after acute poisoning. But in the case of free intake group, it showed very increase through all the breeding period. The weight ratio of organ to body were lowest in the liver of group II in both occasions. The most of cadmium administered were excreted through feces within 2 days after single dose of 100 microgram cadmium. The contents of cadmium in each group were significantly higher than those of control group. In the liver, kidney, spleen and muscle, group II showed the highest level in both occasions of 100 microgram single dose and free intake of water containing 50ppm cadmium. In the skin with hair, group II of the occasion with single dose of 100 microgram and group V with free intake showed the highest level. And the contents of cadmium in tissue were markedly higher in the occasion of free intake of water containing 50ppm cadmium. From the above results I would conclude that the addition of casein and calcium are effective in the inhibition of intension absorption of cadmium esp. by calcium.
OBJECTIVE The effects of exercise on bone density have been found to be inconsistent in previous studies. We conducted a cross-sectional study in premenarcheal girls to test two hypotheses to explain these inconsistencies. Firstly, "the intensity of mechanical strain, in terms of the ground reaction force (GRF), has more important effects on the bone mass at a weight-bearing site", and secondly, "calcium intake modifies the bone response to exercise". METHODS: The areal bone mineral density was measured at the Os calcis, using peripheral dual energy X-ray absorptiometry, in 91 premenarcheal girls aged between 9 and 12 years. The intensity of mechanical strain of exercise was assessed by a self-report questionnaire and scored by the GRF as multiples of body weight, irrespective of the frequency and duration of exercise. The energy and calcium intake were calculated from the 24-hour dietary recall. An analysis of covariance (ANCOVA) was used to determine the interaction and main effects of exercise and calcium on the bone density, after adjusting for age, weight, height and energy intake. RESULTS: The difference in the bone density between moderate and low impact exercise was more pronounced in the high than low calcium intake group. The bone density for moderate impact exercise and high calcium intake was significantly higher than that for low impact exercise (p=0.046) and low calcium intake, after adjusting for age, weight, height and energy intake. CONCLUSIONS: Our study suggests that the bone density at a weight-bearing site is positively related to the intensity of mechanical loading exercise, and the calcium intake may modify the bone response to exercise at the loaded site in premenarcheal girls.