Relationships between anthropometric adiposity indexes and bone mineral density in a cross-sectional Chinese study.

BACKGROUND CONTEXT: Previous studies have reported conflicting results for the relationships between anthropometric adiposity indexes and bone mineral density, based on dual-energy X-ray absorptiometry (DXA). However, few studies were published based on quantitative computed tomography (QCT), especially for Chinese population. PURPOSE: To evaluate the associations of spine bone mineral density (BMD) with body mass index (BMI), waist circumstance (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and a body shape index (ABSI) using QCT. STUDY DESIGN/SETTING: A Cross-sectional study. PATIENT SAMPLE: Around 3,457 participants in multiple communities across 7 administrative regions of China. OUTCOME MEASURES: Spine BMD was measured using QCT, and the classification of osteoporosis was defined as follows: 1) osteoporosis if BMD <80mg/cm3, 2) osteopenia if BMD 80-119 mg/cm3, and 3) normal bone mass if BMD≥120 mg/cm3. METHODS: This study was conducted using convenient sampling between 2013 and 2017. Multivariable linear regression model and logistic regression models were used for the associations of continuous and categorical BMD, respectively. RESULTS: Around 3,405 participants were included in the final analyses, including 1,272 males and 2,133 females, with spine BMD of 111.00±35.47 mg/cm3 and 99.38±40.60 mg/cm3, respectively. Spine BMD decreased significantly with the increase of ABSI in females (adjusted ß, -5.74; 95% confidence interval [CI], -8.50 to -2.98), and this trend also was kept in females aged at less than 60 years (adjusted ß, -14.54; 95% CI, -20.40 to -8.68), and females with age ≥60 years (adjusted ß, -7.59; 95% CI, -10.91 to -4.28). However, this inverse association was observed only in males with age ≥ 60 years (adjusted ß, -5.19; 95% CI, -10.08 to -0.29). Except ABSI, negative associations of Spine BMD with WC (adjusted ß, -0.46; 95% CI, -0.77 to -0.15), WHR (adjusted ß, -6.25; 95% CI, -10.63 to -1.86), WHtR (adjusted ß, -6.80; 95% CI, -11.63 to -1.97) were shown in females aged at <60 years, and positive association with BMI in males with age ≥60 years (adjusted ß, 0.92; 95% CI, 0.29-1.55). CONCLUSIONS: ABSI had more remarkable association with spine BMD, compared with the other four indexes.

The association of calcium intake with osteoporotic vertebral fractures in a large Chinese cohort.

The effect of calcium on prevention of osteoporosis and related fracture which are aging issues is unclear. The aim of this study is to explore the association of calcium intake with vertebral fracture. This study enrolled 3,457 participants from China Action on Spine and Hip Status (CASH) study from 2013 and 2017. Dietary calcium intake was collected using validated food frequency questionnaires (FFQ). Vertebral fracture of CT images was defined as the primary outcome. The mean calcium intake of men and women were 522.75mg/day and 507.21mg/day, respectively. 6% reduction in the odds of fracture risk was observed per 100 unit increase of calcium intake from food among females (OR, 0.94; 95% CI, 0.89-0.99), but results among males were not significant. We divided calcium intake into quintiles when modelling its associations with fracture risk, negative associations of fracture risk with calcium intake were found among females. In a population with low usual calcium intake, higher dietary calcium intake was associated with fewer vertebral fracture in women and that no such association was seen in men.

Associations of anthropometric adiposity indexes with hypertension risk: A systematic review and meta-analysis including PURE-China.

BACKGROUND AND OBJECTIVE: The association between hypertension and obesity has been confirmed, while no agreement has been reached about which anthropometric adiposity index is the best. This meta-analysis aimed to perform a systematic review and meta-analysis on the associations of hypertension risk with body mass index (BMI), waist circumstance (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR), and a prospective urban and rural epidemiology study from China (PURE-China) was added into this meta-analysis as an individual study. METHODS: Systematic literature searching was conducted to identify relevant articles published up to September 2018 in CNKI, WANFANG Data, Web of Science, SinoMed, PubMed, MEDLINE, EMBASE, Cochrane Library and cross-referencing. Literature reporting the association of hypertension risk with BMI, WC, WHR, and WHtR were defined as eligible. PURE-China data were analyzed and included as 1 eligible study into meta-analyses. Summary odds ratio (OR) and area under receiver operating characteristic curve (AUC) were pooled using meta-analysis methods. Heterogeneity and publication bias were evaluated. Subgroups based on gender, country and study design were conducted as well. RESULTS: Thirty-eight original articles including PURE-China were included into meta-analyses, involving 309,585 subjects. WHtR had the strongest association with hypertension risk (OR, 1.68; 95% confidence interval, [CI]:1.29-2.19) and prediction ability (AUC, 70.9%; 95% CI: 67.8%-74.2%), which were also confirmed in subgroup analyses based on gender and country. However, BMI was found to have the highest prediction ability in adjusted models of PURE-China and followed WC, both of which were superior to WHtR (73.7% and 73.4% vs 73.2%). CONCLUSIONS: Our overall meta-analysis further confirmed WHtR as a good indicator at discriminating those individuals at increased risk of hypertension, and in some cases, it is better than BMI, WC, and WHR.

Association patterns of urinary sodium, potassium, and their ratio with blood pressure across various levels of salt-diet regions in China.

We aim to evaluate the association of systolic and diastolic blood pressure (SBP and DBP) with estimated urinary sodium (Na) and potassium(K) excretions, and their gram-to-gram Na/K ratio across various salt-diet regions during 2005-2009 in China. A prospective cohort study was conducted to recruit 46,285 participants in China. A single fasting morning urine specimen was collected to estimate 24-hour urinary Na and K excretion using Kawasaki formula. Means of estimated Na and K were 5.7 ± 1.7 and 2.1 ± 0.5 grams/day, respectively, and mean estimated Na/K ratio was 2.8 ± 0.8. Adjusted analyses showed 1.70 mmHg SBP and 0.49 mmHg DBP increase per 1-g increment of estimated Na, while 1.10 mmHg SBP and 0.91 mmHg DBP decrease for one-gram increase of K. A significant increase in SBP (4.33 mmHg) and DBP (1.54 mmHg) per 1 unit increase in Na/K ratio was observed. More changes of SBP (4.39 mmHg) and DBP (1.67 mmHg) per one-unit increase of Na/K ratio were observed in low-salt regions, though significant changes were also found in moderate- and heavy-salt regions (P for heterogeneity < 0.01). Conclusively, decreasing sodium combined with increasing potassium is likely to have a more beneficial effect than decreasing sodium alone, even if those were living in low-salt regions.