我國南北血壓差異及其膳食因素的作用-營養(yǎng)與血壓的國際

1、我國南北血壓差異及其膳食因素的作用營養(yǎng)與血壓的國際合作研究(INTERMAP Study)趙連成 周北凡 武陽豐1INTERnational collaborative study on MAcronutrients and Blood pressure(Financially supported by NHLBI)INTERMAP 研究簡介2INTERMAP 研究背景一般人群中，人群血壓水平從中年開始明顯增加；而在一些特殊人群中，人群血壓水平?jīng)]有隨年齡增加或增加不明顯；移民流行病學研究提示，人群血壓水平以及血壓隨年齡增加的現(xiàn)象與生活方式有關；已有的研究提示生活方式如膳食因素(BMI、鈉、鉀、

2、飲酒等）因素與血壓有關；缺乏高質量的、大規(guī)模、不同人群背景的研究；3INTERMAP 主要研究目的探討多種膳食營養(yǎng)因素與血壓的關系。4INTERMAP研究特點橫斷面研究；4個國家，17個研究人群；中年人群，4059歲，共4680人；高質量的研究方法，包括統(tǒng)一、高質量的膳食調(diào)查方法；具有可比性的食物成分表評估營養(yǎng)素的攝入量。5INTERMAP Field Centers: China營養(yǎng)與血壓關系的國際合作研究.BeijingShanxiGuangxi6INTERMAP Field Centers: JapanSapporo.ToyamaAito TownWakayama7INTERMAP Ce

3、nters: United Kingdom.BelfastBirminghamLondon (Coordinating Center)8 Minneapolis ChicagoINTERMAP Field Centers: United StatesPittsburghBaltimoreJacksonHoustonCorpus Christi Honolulu.9BackgroundBlood pressure (BP) and prevalence of high BP are greater for northern than for southern Chinese.Although a

4、 few studies suggest that heavier body mass and higher salt intake in the north are related to these BP differences, these unfavorable characteristics only partially explained the north-south BP differences. 10PurposeTo evaluate multiple dietary factors in determining North-South BP differences in C

5、hina.11Study PopulationThere are three Chinese rural samples, two from the North (Pinggu Conuty, Beijing, and Yu County, Shanxi ) and one from the South (Wuming County, Guangxi);Population-based sample;260 persons (1 per family) was randomly selected from each target population, stratified by gender

6、 10-year age group.12MeasurementsField work was conducted in 1997-1998.Each participant attended the local center on four occasions two pairs of consecutive days about 3-6 weeks apart.Blood pressure was measured twice at each visit with a random zero sphygmomanometer.Height and weight without shoes

7、or heavy clothes were measured at the first and third visits. 13Dietary MeasurementsDietary data were collected at each of the four visits by standardized 24-hour dietary recalls.Nutrients were calculated with use of an extensive database, derived from the Chinese national food table and enhanced by

8、 the Nutrition Coordinating Center (NCC), University of Minnesota. Two timed 24-hour urine specimens were collected. Urine aliquots were stored frozen at -20oC and then air-freighted frozen to the Central Laboratory where urinary Na, K, and other indices were measured.14Quality ControlINTERMAP proto

9、col, Manuals of Operation;China addendum to the Nutrition Manual (including Chinese Coding Manual); All stuff trained and certificated;Central training and certification for all dietary interviewers;Dry run;Standard food models, calibrated utensils, scales, pictures,etc.;15Quality Control- continued

10、Collected information from cooks;Monitoring of interviewers during field work;Tape recording of all interviews, review of randomly selected tape and timely feedback to the interviewers;Dietary data coded on survey day; Daily local recording of 10% of recalls by Site Nutritionist and feedback;Recordi

11、ng of 10% of randomly selected recalls by Country Nutritionist and feedback to local centers timely.16Statistical MethodsMeasurements for each individual were averaged across visits. Two northern samples (Beijing and Shanxi) were combined as a “North” sample set (Since BP levels as well as most diet

12、ary and non-dietary variables were similar for them), and Guangxi sample was designated the “South” sample.Multiple linear regression models were used to examine relations of dietary factors to North-South differences in SBP/DBP. 17Average SBP by Sample (Men and Women Combined, N=839)Compared to the

13、 South (Guangxi), all P-values0.001) 18Compared to the South (Guangxi), all P-values0.001) Average DBP by Sample (Men and Women Combined, N=839)19Mean or Prevalence of Selected Variables by Sample (Men and Women Combined, N=839)VariableNorthSouthMale, %49.250.4Age, y48.949.1Education, y5.35.5BMI, kg

14、/m223.8*21.8Heavy activity, h/d0.9*4.0Special diet, %7.5*1.1CVD/DM diagnosis, %9.6*1.8* P0.001 for North vs South (t test or 2 test) 20Mean Nutrient Intake by Sample NutrientNorthSouthEnergy, kcal/day2078*1956Total protein, %kcal11.8*13.8Animal protein, %kcal1.5*4.5Vegetable protein, %kcal10.3*9.3To

15、tal fat, %kcal18.8*22.4SFA, %kcal4.5*6.1Cholesterol, mg/1000kcal86.494.0Carbohydrate, %kcal 67.4*60.2Alcohol, %kcal 2.1*3.5* P0.001 for North vs South (t test or 2 test) 21Mean Nutrient Intake by Sample - continuedNutrientNorthSouthUrinary Na, mmol/24hr271*139Urinary K, mmol/24hr37.1*40.6Urinary Na/

16、K, mmol/mmol7.6*3.7Calcium, mg/1000kcal138*176Magnesium, mg/1000kcal134*198Phosphorus, mg/1000kcal378*562Vitamin A, IU/1000kcal1551*3606Beta-carotene, mcg/1000kcal861*2016Vitamin C, mg/1000kcal36.8*45.0* P0.05Relations of Combinations of Dietary Variables to North-South SBP Differences25* Coefficien

17、t for DBP difference (mm Hg) between the North and the South. Percent reduction in site (North-South)-DBP coefficient compared to Model 1 (without BMI). Percent reduction in site (North-South)-DBP coefficient compared to Model 2 (without BMI). P- value0.05Relations of Combinations of Dietary Variabl

18、es to North-South DBP Differences26SummaryNorthern Chinese had significantly higher SBP/DBP (7.4/6.9 mm Hg higher) than Southerners. In general, Southerners had putatively healthier lifestyles than Northerners, e.g., lower BMI and sodium intake, and higher physical activity and micronutrient intake (vitamin A, vitamin C, calcium, magnesium, phosphorus). Combinations of several dietary variables especially Na, K, phosphorus or magnesium, and BMI reduced North-South BP differences to non-significant level