BACKGROUNDThere are few longitudinal studies on the associations of obesity with hypertension in young adults.

OBJECTIVESTo analyze longitudinally to what extent weight gain associates with hypertension in young adults.

METHODSThe subjects of this study consisted of 6,178 university students (male 4,098; female 2,080). The associations of hypertension with body type change were longitudinally examined by using the records of health examinations while at university. The prevalence ratios (PRs) for hypertension in their senior year were calculated on groups that changed toward obese against those that changed toward underweight. The logistic regression analyses were used to estimate odds ratios (ORs) for hypertension in their senior year of each factor. The analyses were conducted on (i) all subjects, (ii) non-hypertensive subjects in their freshman year, and (iii) by schools, in order to take into account physical activities.

RESULTSThe PRs of hypertension in subjects changed toward obese from their freshmen to seniors against ones toward underweight were 1.47 (95% CI; 1.00-2.15) for males and 3.50 (0.93-13.22) for females. In analyses limited to non-hypertensive subjects in their freshman year, results were similar to those of all subjects. The analyses by school also showed similar results to those including all subjects. In logistic regression analyses, although the factor most strongly associated with hypertension was body type in their senior year, the body type in their freshman still showed significant association with hypertension after the adjustment of senior year body type and hypertension in freshman year. The ORs for hypertension in obese subjects to normal weight ones in their senior year were 9.13 (95% CI; 5.77-14.45) for males and 22.59 (5.69-89.67) for females after adjusted by hypertension in freshman, body type in freshman and school.

CONCLUSIONSThese data suggest that the increase of BMI is linked to hypertension in university students.

OBJECTIVESThe purpose of this study is to define and clarify the causes of differences in physique between urban students and rural students in China.

METHODSSubjects are 2,524 students (male, 838; female, 1686) who entered K University in Shanghai in September, 2001. The data used in this study is based upon K university's Yearly Health Check Record and Students' Family Condition Record. Correlation analysis, analysis of variance (ANOVA) and analysis of covariance (ANCOVA) were applied to analyze the relationships between physique and gross family income, family income per capita, latitude, air temperature, precipitation or altitude.

RESULTSUrban students' height and weight are significantly greater than rural students' in both males and females. Both male students and female students are significantly taller and heavier in accordance with per capita increases in students' family income. The height and weight of male and female students whose parents are peasant farmers are least. With regard to the relationship between physique and urban-rural factors, the F value decreases clearly when family income per capita is taken as a covariate, while the F values slightly decrease also when factors of latitude etc. are taken as covariates. The main cause of differing family income is occupational difference between urban areas and rural ones.

CONCLUSIONStudents born in urban areas are taller and heavier than those born in rural areas. The main cause of these differences is family income per capita. The main cause of variations in family income is the income difference in occupations.