ASSOCIATION BETWEEN URINARY ABNORMALITIES AND ANTHROPOMETRIC INDICATORS IN ITALIAN YOUNG PEOPLE

Introduction and Aims: Over-weight and obesity have increased markedly as an epidemic over the past three decades worldwide. They have been associated with higher occurrence of kidney disease, hypertension and diabetes in adults. Urinary abnormalities may precede onset of many kidney diseases and accompany masked hypertension (HTN). A relationship between over-weight/obesity, urinary abnormalities and HTN has been seldom evaluated in young adults. The main aim of present study was to evaluate whether an association exists between anthropometric indicators, urinary abnormalities and blood pressure levels in a population of young people. Methods: Study population consisted of 17 to 25 year-old students attending Italian high schools who participated in the Italian Kidney Day of years 2010 and 2011.Blood pressure (BP), weight, height, waist circumference (WC) were measured. BMI, Ci and WHt-ratio were calculated. HTN was defined as systolic blood pressure (SBp) ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg. Isolated systolic hypertension (ISH) as SBP ≥ 140 mmHg and DBP ≤ 90 mmHg. According to BMI, normal weight was from 18.5 to 24.9 kg/m2, overweight from 25 to 29.99 kg/m2, class-I obesity from 30 to34.99 kg/m2, class-II from 35-39.99 kg/m2, class-III > 40 kg/m2. Urine test was performed with a dipstick; subjects were considered proteinuric when urine dipstick was positive for proteinuria ≥30 mg/dL. Results: The clinical characteristics of students (n. 4479) are reported in Table 1. At urine dipstick, proteinuria was present in 14,7 %, leucocyturia in 14,5 %, hematuria in 8,6 %. The percentage of adolescents with normal weight was 73,1%, overweight 15,7%, class-I obesity 2,4 %, class-II obesity 0,7 %, class-III obesity 0,1 %. HTN and ISH was present in 1,6 % and 7,6 % of participants, respectively. Data pertaining to participants according to classes of BMI are shown in Table 2. In univariate analysis proteinuria was associated (p=0.01) positively to SBP and pulse pressure but inversely to BMI; no association was found with other variables. Leucocyturia and hematuria had not significant association with any other variables. In multivariable linear regression analysis no predictive factor was found among anthropometric indicators, urinary abnormalities and BP levels. Conclusions: The present study shows that there is no correlation between anthropometric indicators and urinary abnormalities in young people. Plausible explanation may be the fact that overweight or obesity needs more time for causing kidney injury.