Efficacy of dietary guidance to reduce high blood cholesterol in city dwellers : A randomized controlled trial

目的通过对城市居民进行的随机对照试验（RTC），阐明膳食指导对血清总胆固醇（TCH）的降低作用。方法以大阪市A区和大阪府A- i区市民为调查对象。通过电话或信件鼓励参加RTC的人群如下：年龄在40 - 69岁之间，在RCT前6个月进行健康检查时，TCH和HDL-CH的测量值分别在230 - 279 mg/dl之间，低于90 mg/dl。向受试者解释RCT的性质和饮食指导方法，并以书面形式给予知情同意。第一次基线考试分别于一九九七年五月在A区及一九九八年六月在A- i区推行。考生人数为92人，剔除TCH低于230 mg/dl的考生后，A区合格考生56人，i区合格考生19人，共计75人。随机分为干预组（IG）和对照组（CG）。对于前一组，每个月进行三次饮食指导会议，特别关注脂肪摄入量。第一次检查6个月后，两组进行第二次检查。结果IG和CG分别为38和37，年龄、TCH和BMI平均值与第一次检查无明显差异。就IG而言，TCH在第二次检查中从第一次检查的256.5 mg/dl降至231.9 mg/dl。第二次CG显示252.7 mg/dl，低于第一次的256.6 mg/dl。通过饮食指导，TCH的净减少量为20.7 mg/dl。

PurposeTo clarify the lowering effect of serum total cholesterol(TCH) through dietary guidance by randomized controlled trial(RTC) conducted with city dwellers.MethodIt was conducted with citizens in District A in Osaka City and District A-I in Osaka Prefecture. People who were encouraged by telephone or letter to participate in RTC are follows : those aged between 40 and 69, whose TCH and HDL-CH measured at the time of health check-ups 6 months prior to RCT were between 230 and 279 mg/dl, and below 90 mg/dl, respectively. The candidates had the nature of RCT and the dietary guidance method explained to them, and gave informed consent by document.The first baseline examination was implemented in District A in May, 1997 and in District A-I in June, 1998. The number of the examinees was 92, and after eliminating those whose TCH was below 230 mg/dl, the qualified ones numbered 56 in District A and 19 in DistrictA-I, totaling 75. They were divided into two groups by randomized allocation and designated as a intervention group(IG), and a control group(CG). Regarding each one of the former group, three by-monthly dietary guidance sessions took place with a special focus on fat intake. Six months after the first examination, the second one was conducted with both groups.ResultsThe IG and the CG numbered 38 and 37, respectively, It was found that there was no difference in age and the mean measurements of TCH and BMI as found in the first examination.As far as the IG was concerned, TCH went down to 231.9 mg/dl in the second examination from 256.5 mg/dl showed in the first. The CG showed 252.7 mg/dl in the second examination, down from 256.6 mg/dl in the first. The net reduction of TCH through dietary guidance proved to be 20.7 mg/dl.