Background
The purpose of this study was to examine the association between the change of parental weight status and the change of their child's weight status over 2 years. Methods: A total of 379 children ages 11-13 years were measured their height and weight in 2001 and 2003. Their parents completed a questionnaire including self-reported parental weight and height during the same period. Parental weight status was classified as overweight (BMI≥25 kg/m²) and non-overweight (BMI＜25 kg/m²). Children's weight status was classified as overweight and non-overweight using the age and gender-specific BMI established by the Korean Academy of Pediatrics. The weight status over 2 years was categorized as a group of persistent overweight, persistent non-overweight, shifting overweight to non-overweight, and shifting non-overweight to overweight. Results: After adjusting for the child's gender and the father's weight status, the odds ratio for being persistently overweight over 2 years in a child having a mother with persistent overweight was 2.8 (95% CI: 0.9-8.5) compared to a child having a mother with persistent non-overweight. Likewise, the odds ratio for being persistently overweight over 2 years in a child having a father with persistent overweight was 2.9 (95% CI: 1.4-6.1) compared to the child having a father with persistent non-overweight. Conclusion: Parental weight status over 2 years was associated with the 2-year weight status in children. The parents- and family-based intervention are needed to prevent and manage childhood obesity. (J Korean Acad Fam Med 2008;29:336-341)

Background
: Body mass index is currently applied as the diagnostic standard of overweight and obesity, regardless of age. Percentage body fat ratio applies separate standards among different sex, but does not have separate standards for different age groups. Since body mass index and percentage body fat may differ according to age, we conducted this study to see if a separate standard for overweight and obesity is indeed necessary for different age groups.

Methods : We selected 2,190 subjects, who were the 10 percent picked randomly by computer, among 21,921 clients who had visited the St. Mary's Hospital's health promotion center in Seoul. Those diagnosed with diabetes, thyroid disease, renal failure, and tuberculosis were excluded, leaving 1,939 over the age of 20, as final subjects. Anthropometric measurements were done using electronic scales and height meters, while body composition was measured with a multi-frequency bioelectric impedance analysis (Inbody 3.0 Biospace, Seoul). The results of this study were shown in mean and standard deviation, and mean values according to ages were compared by Ancova test.

Results : In the case of adult men, percentage body fat increased with age. This was observed especially with subjects over 30 compared to subjects in their 20s, although not proven to be statistically significant. A decrease in fat free mass rather than increase in body fat mass was noted with aging. With adult women, percentage body fat increased markedly with subjects over 50, mainly due to increased body fat mass rather than decreased fat free mass. Subjects exceeding a body mass index of 25, which is the standard limit of body mass index for obesity, was 60th percentile for adult men, and 70∼80th percentile for adult women. Percentage body fat in this case was 22.54% for men and 31.99∼33.46% for women.

Conclusion : Our study indicates that both men and women show changes in body mass index and fat free mass with aging. Hence, there are limitations to applying a universal standard for body mass Index, regardless of age. We suggest that further studies on standards for adult obesity should be conducted based on specific Korean epidemiologic data.

Background
: Obesity has been generally diagnosed by 'Body Mass Index (BMI)' in primary care. Recently the use of Bioelectrical Impedance Analyzer' has become popular in Korea to evaluate body fat rate (BFR), as cost is inexpensive and the method to use is simple. As a result, the opposed finding of normal BMI and elevated BFR vice versa in same individuals are being encountered frequently. We designed this study to find out the characteristics and cardiovascular risk of people in these groups.

Methods : The medical records of health promotion center were obtained and 22,704 applicants visitor who undeerwent health risk questionnaire, screening tests and physical examination for cardiovascular disease were reviewed.

Results : After adjusting for age, sex, exercise and education level, cardiovascular risk such as hypertension, DM, and hypercholesterolemia, LDL tended to increase linearly and HDL tended to decrease linearly with increase of BFR or BMI. In comparison with normal BMI and BFR group, the odds ratios of normal BMI and elevated BFR group or vice versa were increased.

Conclusion : If either one of BMI or BFR of a person was elevated, even though the other was within normal range, the cardiovascular risk of that person was shown to be high.

Background
: This is a cross-sectional study to assess the effect of BMI (body mass index) on blood pressure and to get the appropriate BMI range for the prevention and control of hypertension in old men and women.

Methods : From 1996 to 1998 we obtained data for anthropometrics, blood pressure, serum blood profiles and health behaviors about 418 out of 668 old people having visited a charge-free clinic in rural areas. First we tried to figure out the relationship between BMI and systolic or diastolic blood pressure in old men and women separately. After adjusting age, smoking , alcohol, blood glucose, total cholesterol, we checked the linear relationship between each quintile BMI group and prevalence of hypertension in old men and women and obtained prevalence odds ratio (POR) for hypertension in each the 2nd to the 5th quintile BMI group compared to the baseline hypertension- prevalence of the1st quintile BMI group.

Results : Regardless of sex, there was significant correlations between BMI and systolic blood pressure (in men r=0.257, p=0.002;in women r=0.182 p=0.005) or diastolic blood pressure (in men r=0.204, p=0.014;in women r=0.256 p<0.001). The prevalence of hypertension in men and women increased 1.37 and 1.41 times respectively by each quintile BMI increase. According to each BMI group in men (median BMI value of each quintile group:18.2, 20.4, 21.8, 23.3, 26.6 kg/㎡), PORs for hypertension were 1.0, 3.7(95% C.I;1.05-12.68), 3.6(95% C.I;1.03-12.59), 6.5(95% C.I;1.89-22.29), 4.0 (95% C.I;1.11-14.36). In women, (median BMI value of each quintile group;18.6, 21.3, 22.9, 25.1, 28.3 kg/㎡), PORs for hypertension were 1.0, 1.6(95% C.I;0.62-3.82), 2.9(95% C.I;1.22-6.99), 2.9(95% C.I;1.28-6.68), 4.2(95% C.I;1.73-9.98).

Conclusion : Regardless of sex, there was a significant positive association between BMI and prevalence of hypertension in the old and the risk of hypertension increased even in normal weight group compared to the underweight group. Further studies on the appropriate to prevent and control hypertension in old people will be needed.