Hypothalamic-pituitary-adrenal axis and sympathetic nervous system activities in Pima Indians and Caucasians

Tataranni, P. Antonio; Cizza, Giovanni; Snitker, Søren; Gucciardo, Frank; Lotsikas, Angela; Chrousos, George P.; Ravussin, Éric

doi:10.1016/s0026-0495(99)90092-6

Cited by 21 publications

(11 citation statements)

References 24 publications

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“…The Pima Indians of Arizona present significant interest in this respect because they have the highest reported prevalence of obesity in the world, but a relatively low prevalence of hypertension and atherosclerotic disease [76][77][78]. Compared with whites, Pima Indians have a higher percentage of body fat and higher fasting plasma insulin concentrations and insulin resistance, even after controlling for body size [79,80], but lower MSNA [75,[81][82][83]. The lack of increase in MSNA with increasing adiposity and insulinemia in Pima Indians may explain, in part, why this population has a low tendency for hypertension despite the high prevalence of obesity and hyperinsulinemia.…”

Section: Genetic and Ethnic Differences Modify The Association Of Obementioning

confidence: 99%

New developments in the pathogenesis of obesity-induced hypertension

Kotsis

Nilsson

Grassı

et al. 2015

Journal of Hypertension

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Obesity is a disorder that develops from the interaction between genotype and environment involving social, behavioral, cultural, and physiological factors. Obesity increases the risk for type 2 diabetes mellitus, hypertension, cardiovascular disease, cancer, musculoskeletal disorders, chronic kidney and pulmonary disease. Although obesity is clearly associated with an increased prevalence of hypertension, many obese individuals may not develop hypertension. Protecting factors may exist and it is important to understand why obesity is not always related to hypertension. The aim of this review is to highlight the knowledge gap for the association between obesity, hypertension, and potential genetic and racial differences or environmental factors that may protect obese patients against the development of hypertension and other co-morbidities. Specific mutations in the leptin and the melaninocortin receptor genes in animal models of obesity without hypertension, the actions of α-melanocyte stimulating hormone, and SNS activity in obesity-related hypertension may promote recognition of protective and promoting factors for hypertension in obesity. Furthermore, gene-environment interactions may have the potential to modify gene expression and epigenetic mechanisms could also contribute to the heritability of obesity-induced hypertension. Finally, differences in nutrition, gut microbiota, exposure to sun light and exercise may play an important role in the presence or absence of hypertension in obesity.

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Section: Genetic and Ethnic Differences Modify The Association Of Obementioning

confidence: 99%

New developments in the pathogenesis of obesity-induced hypertension

Kotsis

Nilsson

Grassı

et al. 2015

Journal of Hypertension

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“…On the other hand, several experiments clearly showed that lipids may alter autonomic nervous system activity in humans (16,17). More precisely, clinical and epidemiological studies showed that reduced autonomic activity, especially sympathetic, might be involved in the onset of obesity (18,19). Particularly in Pima Indians, a low sympathetic nervous system activity is also described as a predictor of weight gain (20).…”

Section: Fas and Nervous Control Of Insulin Secretionmentioning

confidence: 99%

Fatty Acid Signaling in the Hypothalamus and the Neural Control of Insulin Secretion

Migrenne

Cruciani-Guglielmacci

Lee

et al. 2006

Diabetes

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It is now clearly demonstrated that fatty acids (FAs) may modulate neural control of energy homeostasis and specifically affect both insulin secretion and action. Indeed, pancreatic ␤-cells receive rich neural innervation and FAs induce important changes in autonomic nervous activity. We previously reported that chronic infusion of lipids decreased sympathetic nervous system activity and led to exaggerated glucose-induced insulin secretion (GIIS), as would be expected from the known inhibitory effect of sympathetic splanchnic nerve activity on insulin secretion. Intracarotid infusion of lipids that do not change plasma FA concentrations also lead to increased GIIS. This effect of FAs on GIIS was prevented by inhibition of ␤-oxidation. It is noteworthy that a single intracarotid injection of oleic acid also induced a transient increase in plasma insulin

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“…20,22 Compared with whites, Pima Indians have, on average, a higher percentage of body fat and higher fasting plasma insulin concentrations, even after controlling for body size and the degree of insulin resistance, 23,24 but lower SNS activity. 19,25,26 On the basis of these findings, it appears that the interrelation between adiposity, insulinemia, SNS activity, and BP may differ between Pima Indians and whites. To further examine these relations and to revisit Landsberg's hypothesis, 2 we analyzed data from a large number of normotensive Pima Indian and white men characterized for body composition, glucose tolerance, fasting plasma insulin concentration, resting heart rate (HR) and BP, and in whom postganglionic efferent sympathetic discharge rates to skeletal muscle (MSNA, muscle sympathetic nerve activity) were recorded directly by microneurography as a measure of SNS activity.…”

mentioning

confidence: 94%

Ethnic Differences in Insulinemia and Sympathetic Tone as Links Between Obesity and Blood Pressure

et al. 2000

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Abstract-Hyperinsulinemia and increased sympathetic nervous system (SNS) activity are thought to be pathophysiological links between obesity and hypertension. In the present study, we examined the relation among heart rate (HR), blood pressure (BP), and percent body fat (hydrodensitometry or DEXA), fasting plasma insulin concentration, and muscle sympathetic nerve activity (MSNA, microneurography) in male, normotensive whites (nϭ42) and Pima Indians (nϭ77). Pima Indians have a high prevalence of obesity and hyperinsulinemia but a relatively low prevalence of hypertension. Compared with whites, Pima Indian men had a higher percent body fat (28% versus 21%) and higher fasting insulin concentrations (210 versus 132 pmol/L) but lower MSNA (27 versus 33 bursts/min) (all PϽ0.001). In both ethnic groups, HR and BP were positively related to percent body fat and MSNA, and both were significant independent determinants of HR and BP in multiple regression analyses. However, MSNA was positively related to percent body fat and the fasting insulin concentration in whites (rϭ0.60 and rϭ0.47, both PϽ0.01) but not in Pima Indians (rϭ0.15 and rϭ0.03, NS) (PϽ0.01 for ethnic differences in the slope of the regression lines). These results confirm the physiological importance of the SNS in normal BP regulation but indicate that the roles of hyperinsulinemia and increased SNS activity as mediators for the relation between obesity and hypertension can differ between different ethnic groups. The lack of an increase in SNS activity with increasing adiposity and insulinemia in Pima Indians may contribute to the low prevalence of hypertension in this population. (Hypertension. 2000;36:531-537.)Key Words: adipose tissue Ⅲ hyperinsulinism Ⅲ autonomic nervous system Ⅲ hypertension, obesity Ⅲ ethnic groups O besity is associated with an increased risk of cardiovascular diseases including hypertension, stroke, and coronary artery disease. 1 The pathophysiological mechanisms predisposing obese individuals to hypertension are not fully understood, but hyperinsulinemia and increased sympathetic nervous system (SNS) activity have been suggested to play a role. 2-6 Almost 15 years ago, Landsberg 2 proposed that the hyperinsulinemia associated with obesity-related insulin resistance leads to increased SNS activity, which in turn contributes to increased blood pressure (BP) through chronotropic, vasoconstrictive, and antinatriuretic effects. Although there is both epidemiological and experimental evidence to support the links between obesity/hyperinsulinemia and increased SNS activity 2-10 and between hyperinsulinemia/increased SNS activity and hypertension, 2-6,11,12 some studies provide conflicting results. [13][14][15][16] Thus, the potential role of hyperinsulinemia and increased SNS activity in the pathogenesis of obesity-related hypertension remains controversial. 17,18 Ethnicity may be an important factor to consider since insulinemia, SNS activity, and the propensity for obesity and hypertension all differ substantially among different popul...

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Hypothalamic-pituitary-adrenal axis and sympathetic nervous system activities in Pima Indians and Caucasians

Cited by 21 publications

References 24 publications

New developments in the pathogenesis of obesity-induced hypertension

New developments in the pathogenesis of obesity-induced hypertension

Fatty Acid Signaling in the Hypothalamus and the Neural Control of Insulin Secretion

Ethnic Differences in Insulinemia and Sympathetic Tone as Links Between Obesity and Blood Pressure

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