Effect of dietary electrolytes upon calcium excretion: the Yi People Study

OBJECTIVE

To investigate the relations of dietary sodium, potassium, calcium and magnesium with urinary calcium excretion.

DESIGN

Cross-sectional epidemiologic study of 417 Chinese men with a wide variation of electrolyte intakes.

METHODS

Three consecutive 24-h dietary recall data and three 24-h urinary samples were obtained on the same days. Urinary analyses included calcium, sodium, potassium, magnesium and creatinine. A fasting blood sample was obtained on the first morning, and serum analyses included electrolytes, creatinine and urea nitrogen. Correlation and regression analyses were used to examine the relation between electrolyte intake and calcium excretion.

RESULTS

Whilst urinary calcium was not related to dietary calcium, it was significantly correlated with dietary sodium and potassium. A linear relationship was seen between dietary sodium, potassium and urinary calcium. After adjustment for age, body mass index, serum creatinine, dietary calcium intake and other electrolytes, urinary calcium was positively related to dietary sodium and negatively related to dietary potassium. This relation was seen at different levels of dietary calcium intake. The relation between magnesium intake and calcium excretion was inconsistent.

CONCLUSION

These results suggest that sodium and potassium intake influence urinary calcium excretion in normotensive men.

[Rapid diagnosis of pulmonary Pseudomonas aeruginosa infections by indirect immunofluorescent antibody]

167 sputum specimens collected from patients with pulmonary infection were tested by IFA (Indirect immunofluorescent antibody-staining) with serogroup-specific monoclonal antibody to Pseudomonas aeruginosa, compared with quantitative sputum culture. The results showed the minimum concentration of bacteria detectable by IFA was 10 cfu/ml. 31(86.1%) were positive in 36 specimens with more than 10 cfu/ml of Pseudomonas aeruginosa. 22(100%) were positive in 22 specimens with more than 10 cfu/ml of Pseudomonas aeruginosa. In 127 specimens with a negative culture for Pseudomonas aeruginosa, 121(95.2%) were negative, 6(4.8%) were false-positive which could be identified by Gram's-staining. The type of Pseudomonas aeruginosa could also be identified within 3 hours.

Relation of serum zinc and copper to lipids and lipoproteins: the Yi People Study

The relations of serum zinc (Zn) and copper (Cu) to serum total cholesterol (TC), low-density-lipoprotein and high-density-lipoprotein cholesterol (LDL-C and HDL-C) and triglycerides were investigated in a population-based sample of 399 men in Southern China. Serum Cu was inversely related to HDL-C (r = -0.21), while Zn/Cu ratio showed a positive association (r = 0.19). These relationships remained significant after adjusting for age, body mass index (kg/m2), physical activity, tobacco smoking and dietary cholesterol, fat, and fiber. While no significant association was observed between serum Cu and serum TC in univariate analysis, a significant negative association was observed in multivariate analysis, after adjustment for the above mentioned independent variables. No significant association between serum Cu and LDL-C was found. These observations, as well as those reported in other studies reviewed herein, suggest that Cu is implicated in the metabolism of HDL-C, although the mechanism involved is not fully understood. No significant associations were found between serum Zn and the lipid variables.

Effect of migration on blood pressure: the Yi People Study

The Yi People Study was conducted in Puge County, Sichuan Province, People's Republic of China. Four population groups were surveyed for risk factors for cardiovascular disease. Included were two groups of Yi farmers living either in a high mountainous area in extremely remote villages at or above 2,750 meters elevation, or in a mountainside area at about 1,800 meters elevation. A third study group consisted of Yi farmers who migrated to the county seat during the 1950s. Local residents of the county seat, the Han people, constituted the fourth group. Blood pressure rises very little with age after puberty in Yi farmers, but there was a trend of increasing blood pressure with age in Yi migrants and Han. Mean body mass index (kg/m2) and heart rate were higher in Yi migrants than in Yi farmers. For men, both systolic and diastolic blood pressure were greater among Yi migrants than among Yi farmers. These differences persisted after adjusting for age and body mass index. Among women, after adjusting for age, BMI, and altitude, only diastolic blood pressure was lower among Yi farmers than Yi migrants. Yi migrants and Han had similar blood pressures. In 1986, a sample of men participated in more detailed studies of diet, serum, and urine. The proportion of energy from fat ranged from less than 10% among high-mountain Yi farmers to almost 40% among Yi migrants and Han. Compared with Yi farmers, Yi migrants consumed more sodium and less potassium, calcium, and magnesium, had lower serum potassium, and a greater sodium/potassium ratio. Urinary excretion of sodium, calcium, and the sodium/potassium ratio were all greater in Yi migrants than in Yi farmers, while the reverse was seen for potassium. These data suggest that changes in life-style, including dietary changes, contribute importantly to the higher blood pressure among Yi migrants.

Relation of electrolytes to blood pressure in men. The Yi people study

The relations of sodium, potassium, calcium, and magnesium to blood pressure were investigated in four groups of men (119 high-mountain Yi farmers, 114 mountainside Yi farmers, 89 Yi migrants, and 97 Han people) with a wide range of electrolyte intake in Puge County, Sichuan Province, People's Republic of China. Electrolytes were measured in diet, serum, and urine. Sodium excretion was 73.9 mmol/24 hr in high-mountain Yi farmers, 117.9 mmol/24 hr in mountainside Yi farmers, 159.4 mmol/24 hr in Yi migrants, and 186.0 mmol/24 hr in the Han people. In ecological correlation analysis, dietary and urinary sodium were significantly and positively correlated with both systolic and diastolic pressure, whereas serum sodium showed no relation with blood pressure. In diet, serum, and urine, potassium was negatively related to systolic and diastolic pressure, whereas the sodium/potassium ratio showed a positive association. With regard to calcium, only urinary excretion was significantly and positively related to blood pressure. No relation was found between magnesium and blood pressure. Analyses at the individual level confirmed the results for sodium and potassium seen at the ecological level, but in addition, dietary calcium and magnesium were significantly and negatively correlated to both systolic and diastolic pressure, and urinary magnesium was inversely related to diastolic pressure. These relations persisted after controlling for age, body mass index (kg/m2), heart rate, alcohol, and total energy intake in multiple regression analysis performed separately for electrolytes in diet, serum, and urine. In multiple regression analysis, an increase in sodium intake of 100 mmol/day corresponded to an increase of 2.3 mm Hg systolic blood pressure and 1/8 mm Hg diastolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence of chromosome diseases in the general population of Sichuan, China

Chromosome abnormalities with recognizable clinical manifestations including mental retardation, primary infertility or primary amenorrhea of unknown etiology, abnormal sex differentiation and abnormal sex development were surveyed in the general population of Sichuan. The results showed that the prevalence of chromosome diseases in Sichuan was 31.5 per 100,000 of the general population with almost equal frequencies for autosomal chromosome and sex chromosome diseases. The most frequent autosomal chromosome disease was Down syndrome. The prevalence was 14.2 per 100,000 for the total population, and there should therefore be 154,000 cases of Down syndrome in the whole of China with its population of 1,100 million people. The most frequent sex chromosome diseases were Turner syndrome and Klinefelter syndrome. The prevalences were 14.3 and 14.1 per 100,000 for females and males, respectively. The majority of autosomal chromosome diseases clustered in the younger age groups, while the highest detection rate of sex chromosome diseases was found in the age group of 25-35, and thereafter it decreased with age. The age distribution of the cases indicates that both autosomal and sex chromosome diseases reduce the lifespan of patients.

5p;12q translocation with manifestations of cri du chat syndrome and Marfanoid arachnodactyly

A 12-year-old boy with a history of a mewing cry after birth, severe mental retardation, Marfanoid arachnodactyly, general osteomalacia and multiple bone fractures was found to have a de novo 5p;12q chromosomal translocation. The karyotype is 46,XY,t(5;12)(12qter----12q24.1::5p15----cen----5qt er; 12pter----cen----12q24.1). The karyotypes of other examined family members are normal. The manifestations of cri du chat syndrome are explained by the loss of a small segment of 5p15 which is responsible for the major stigmata of the syndrome, and the abnormalities of the osseous system may be the results of untreated vitamin D resistant rickets.

Urinary electrolytes and blood pressure in three Yi farmer populations, China

The relation between blood pressure and urinary electrolytes, including sodium, potassium, calcium, and magnesium were examined in male farmers of the Yi nationality who live in three separate communities in Sichuan and Yunnan provinces in China, where the lifestyles, habits, and living conditions are very different. One of these three communities was unacculturated and had the lowest average blood pressure as well as the lowest prevalence rate of hypertension in China; one was acculturated and had the highest average blood pressure; and the third was moderately acculturated with its average blood pressure between the other two. Blood pressure was taken on each of 3 days and corresponding 24-hour urine specimens were collected to measure potassium, sodium, calcium, magnesium, urea nitrogen, and creatinine. Ecological and individual-based data correlation analyses were employed to study the relations among age, body mass index, some related indexes of electrolyte derivatives, and blood pressure. Multiple regression analyses were used to explore the relation of blood pressure to the above indexes, adjusted for age, body mass index, urea nitrogen and creatinine, and geographical differences. Statistically significant correlation analyses showed that systolic blood pressure was positively associated with sodium-creatinine, calcium-creatinine, sodium-potassium, calcium-magnesium, and urea nitrogen and creatinine ratios; negatively associated with potassium-creatinine and magnesium-creatinine ratios. The ridge regression analysis selected only calcium-magnesium ratio as a predictor of systolic blood pressure.