Association between nocturnal blood pressure dipping and insulin resistance in children affected by NAFLD

The aim of this study was to analyse the relationship between insulin–glucose metabolism, nocturnal blood pressure dipping and nonalcoholic fatty liver disease (NAFLD) in obese adolescents without diabetes. One hundred one consecutive children, with biopsy-proven NAFLD, were included in this study. Blood samples were drawn for the analyses of liver function tests, insulin–glucose metabolism and lipid profile appraisal. An ambulatory blood pressure measurement (ABPM) was performed. Seventy-six children (75.3 %) were systolic nondippers, and 23 of them were diastolic nondippers (30.3 %). No differences were found in the anthropometric parameters between the two groups. When compared to the systolic dippers, the systolic nondippers had higher medians of mean nocturnal blood pressure, glucose at 0, 60 and 120 min in the oral glucose tolerance test (OGTT), OGTT insulin at all time points and insulin-resistance values. No correlation of histopathological features with dipping/nondipping statuses was found. Conclusions: We found an association between a nocturnal blood pressure fall and measures of insulin levels, independent of obesity, or daytime blood pressure levels, among the obese patients with NAFLD. Although no association between nondipping profiles and NAFLD was observed in our study, further studies with a longer term follow-up are needed, to better elucidate the complex link between these particular entities.