Added Impact of Obesity and Insulin Resistance in Nocturnal Blood Pressure Elevation in Children and Adolescents

Abstract

Abstract-The aim of the present study was to analyze the relationship between insulin resistance and the ambulatory blood pressure components in obese children and adolescents. Eighty-seven overweight and obese white children and adolescents of both sexes, of European origin from 6 to 18 years of age (mean age: 10.9Ϯ2.7 years), were selected. Obesity was defined on the basis of a threshold body mass index z score Ͼ2 (Cole's least mean square method) and overweight with a body mass index from the 85th to 97th percentile. A validated oscillometric method was used to measure ambulatory BP (Spacelabs 90207) during 24 hours. Fasting glucose and insulin were measured, and the homeostasis model assessment index was calculated. Subjects were grouped into tertiles of homeostasis model assessment index. No significant differences in terms of age, sex, and body mass index z score distribution were observed among groups. When adjusted by age, sex, and height, nocturnal systolic blood pressure and heart rate were significantly higher in subjects in the highest homeostasis model assessment index tertile (Ͼ4.7) as compared with those of the other groups, whereas no differences were observed for awake systolic blood pressure or heart rate. Whereas body mass index z score was more closely related with blood pressure and heart rate values, waist circumference was strongly related with insulin resistance. Moreover, both waist circumference and insulin resistance were mainly associated with higher nocturnal but not with awake blood pressure. The early increment of nocturnal blood pressure and heart rate associated with hyperinsulinemia may be a harbinger of hypertension-related insulin resistance and may contribute to heightened cardiovascular risk associated with this condition. Key Words: obesity Ⅲ insulin resistance Ⅲ nocturnal blood pressure Ⅲ heart rate Ⅲ children Ⅲ adolescents T he prevalence of obesity is continuously increasing among children. 1,2 The adverse effects of weight gain on metabolic and cardiovascular function and the association of weight gain with a higher incidence of health problems later in life represent major issues in health care, which have generated great concern over the last few years. [3][4][5][6] Indeed, considering the increasing tendency for obesity to appear during childhood and to track, to some extent, into adult life, 7,8 as well as the firmly established relationships among obesity, type 2 diabetes, and hypertension in adults, obese children appear to be at particularly high risk of becoming diabetic and hypertensive as they age. 9 Blood pressure (BP) values in childhood represent the most important measurable marker of the potential level of cardiovascular risk later in life. 10 This strongly supports the importance of performing careful and repeated BP measurements during childhood and adolescence. Solid evidence collected over the last 20 years has demonstrated the high prognostic power of ambulatory BP monitoring (ABPM). Indeed, 24-hour BP values have been significantly better predictors...

Association between nocturnal blood pressure dipping and insulin metabolism in obese adolescents

“…However, we found no associations between dipping and insulin sensitivity (S i ) or glucose metabolism (P-glucose, glycosylated hemoglobin Alc, disposition index or glucose efficiency). To our knowledge, there is only one study 9 that analyzed the association between dipping and insulin-glucose metabolism in obese, non-diabetic adolescents. Lurbe 9 reported higher sleep systolic BP, but not day:night ratio, among overweight and obese children with a high as compared with a low HOMA index.…”

“…8 Among children, chronic poor glycemic control may place patients with type 1 diabetes at risk for higher nocturnal BP 4 and fasting insulin (fS-insulin) or HOMA is positively associated with sleep BP among obese children. 9 Obese, but otherwise healthy, adolescents are at higher risk of unfavorable glucose metabolism 10 as well as reduced nocturnal BP dipping 2 compared with normal-weight peers. However, there have only been few studies 9 analyzing the association between insulin-glucose metabolism, nocturnal dipping in obese and non-diabetic adolescents.…”

“…9 Obese, but otherwise healthy, adolescents are at higher risk of unfavorable glucose metabolism 10 as well as reduced nocturnal BP dipping 2 compared with normal-weight peers. However, there have only been few studies 9 analyzing the association between insulin-glucose metabolism, nocturnal dipping in obese and non-diabetic adolescents.…”

Salt sensitivity and circadian rhythm of blood pressure: the keys to connect CKD with cardiovasucular events

“…Therefore, in the salt-sensitive state, several risk factors are clustered together, leading to future cardiovascular events and renal failure. 20,21,26,[82][83][84][85][86] In our follow-up study 20 of essential hypertensive patients with known salt sensitivity, 31 cardiovascular events were documented during the follow-up period. Of these, 21 were stroke.…”

Nocturnal blood pressure but not insulin resistance influences endothelial function in treated hypertensive patients

“…IR is a metabolic perturbation and seems to be related to endothelial dysfunction in normotensive offspring of subjects with arterial hypertension as well as in hypertensive patients. 30 Lurbe et al 31 found a strong relationship between IR, determined by HOMA and increased nocturnal blood pressure in a large cohort of obese children. Both, IR and elevated nocturnal blood pressure seem to be predictive of renal disease and cardiometabolic syndrome.…”