engleski

Tubular proteinuria as an early sign of renal damage in prehypertension.

Introduction and Aims: Prehypertension is known to be associated with increased cardiovascular risk. Only a few studies about the association between prehypertension and renal disease have been performed so far. The aim of our study was to analyse differences in characteristics of prehypertensive and normotensive subjects, with an emphasis on renal function. Methods: A total of 2489 subjects were enrolled in a Croatian rural study, out of which 592 (240 male, 352 female) were eligible for further analysis. The exclusion criteria were hypertension, diabetes mellitus, pregnancy, chronic terminal disease, dementia, immobility and missingdata. Blood pressure (BP) was measured following the ESH/ESC guidelines. BMI and waist circumference (WC) were determined. Fasting blood was analysed for glucose (FBG), insulin, total-cholesterol (T-C), HDL, LDL, triglycerides (TG), serum creatinine, haematocrite (Hct), C reactive protein (CRP) and white blood cell count (WBC). HOMA index was used to calculate insulin resistance while abbreviated MDRD formula to estimate glomerular filtration rate (eGFR). Albumin to creatinine ratio (ACR) and alpha1microglobuline to creatinine ratio (alpha1CR) were determined. Subjects were divided into normotension group (BP<130/85, N=448) and prehypertension group (BP=130/85-139/89, N=144) and additionally into three subgroups depending on their age: group I (<35 years of age, N=235), group II (35-55 yrs, N=260) and group III (>55 yrs, N=97). Kruskal-Wallis and Mann Whitney tests were used while significance was set at 0.05. Results were expressed as median and interquartile ranges. Results: Overall, prehypertensives were significantly older, more obese, dyslipidemic, had higher CRP, Hct and HOMA index values than normotensives (p<0.05). Additionally, they also had significantly higher ACR and alpha1CR than normotensives (4.99 {; ; ; ; ; 3.42-7.53}; ; ; ; ; vs. 4.09 {; ; ; ; ; 3.01- 6.30}; ; ; ; ; , p=0.003 ; 4.89 {; ; ; ; ; 3.16-7.61}; ; ; ; ; vs. 4.21 {; ; ; ; ; 2.90- 6.25}; ; ; ; ; p=0.009, respectively), while a trend of lower eGFR was found within prehypertensive group compared to normotensives (80.56 {; ; ; ; ; 71.95-90.80}; ; ; ; ; vs. 81.30 {; ; ; ; ; 72.79- 91.15}; ; ; ; ; . Interestingly, observing 3 different age groups we found that in group I (<35 years of age) prehypertensive subjects had higher values of alpha1CR, BMI, WC, FGB, T-C, LDL, TG, CRP and HOMA index (p<0.05) and a trend of higher ACR and lower eGFR. On the contrary, in group III (>55 years of age) prehypertensive persons differed form normotensives only in BMI and FBG (p<0.05), but not in the other parameters including biomarkers of renal function. Conclusions: Prehypertensives significantly differ from normotensives not only in metabolic disturbances but also in renal function, difference being significant mostly in persons younger than 35 years of age. Higher values of alpha1 microglobulinuria might point on early proximal tubule damage in prehypertension.

Prehypertension; cardiovascular risk; renal disease

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