Salt loads raise plasma fatty acids and lower insulin.

Goodfriend, Theodore L.; Ball, Dennis L.; Weinberger, Myron H.; Moore, Thomas J.; Weder, Alan B.; Egan, Brent M.

doi:10.1161/01.hyp.17.6.958

Cited by 24 publications

(14 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Adipocyte hypertrophy may potentiate the insulin resistance in OP rats, due to the increased fatty acids efflux and increased circulating triglycerides. It was shown that salt increases circulating levels of fatty acids (17), and our data indicating adipocyte hypertrophy suggest a possible increase in circulating fatty acids.…”

Section: Discussionsupporting

confidence: 60%

“…Some forms of hypertension in humans, including essential hypertension associated with obesity, are influenced by an increase in the amount of dietary salt intake (17,53). The aim of the present study was to assess the effect of increased salt intake on the development of hypertension and associated mechanisms involving oxidative stress and endorgan damage in obese rats.…”

Section: Discussionmentioning

confidence: 95%

See 1 more Smart Citation

Effect of salt on hypertension and oxidative stress in a rat model of diet-induced obesity

Dobrian

Schriver

Lynch

et al. 2003

American Journal of Physiology-Renal Physiology

View full text Add to dashboard Cite

. Effect of salt on hypertension and oxidative stress in a rat model of diet-induced obesity. Am J Physiol Renal Physiol 285: F619-F628, 2003. First published June 10, 2003 10.1152 10. /ajprenal.00388. 2002 diet is known to induce or aggravate hypertension in animal models of hypertension and in humans. When Sprague-Dawley rats (n ϭ 60) are fed a moderately high-fat diet (32% kcal fat, 0.8% NaCl) for 10 wk, about one-half develop obesity [obesity prone (OP)] and mild hypertension, whereas the other half [obesity resistant (OR)] maintain body weight equivalent to a low-fat control (C) and are normotensive. The aim of this study was to test the effect of high-NaCl diets (2 and 4% NaCl) on the development of hypertension and obesity, oxidative stress, and renal function. Both 2 and 4% NaCl induced an early increase in systolic blood pressure of OP but not OR or C rats. High-salt intake induced an increase in the size and reduction in number of adipocytes, concomitant to a twofold increase in circulating leptin in OP rats. Aortic superoxide generation indicated a 2.8-fold increase in the OP high-salt vs. normalsalt groups, whereas urine isoprostanes were not significantly increased. Also, hydroxynonenal protein adducts in the kidney were highly increased in OP rats on 2 and 4% NaCl, indicating oxidative stress in the renal tissue. Urine albumin was increased threefold in the OP on 2% NaCl and fourfold in the same group on 4% NaCl vs. 0.8% NaCl. Kidney histology indicated a higher degree of glomerulosclerosis in OP rats on high-salt diets. In summary, high-salt diet accelerated the development but did not increase the severity of hypertension; high salt increased oxidative stress in the vasculature and kidney and induced kidney glomerulosclerosis and microalbuminuria. Also, the OP rats on high salt displayed adipocyte hypertrophy and increased leptin production.glomerulosclerosis; kidney; leptin; sodium dietary OBESITY IS A complex, multifactorial disease that is associated with essential hypertension in ϳ78% of men and ϳ65% of women, as indicated by the data from the Framingham Heart Study (25). Another important contributor to hypertension in humans is the excessive consumption of dietary salt, and epidemiological studies have demonstrated a significant but weak relation between salt intake and hypertension (32, 33). Some, but not all, interventional studies have shown that salt restriction may lower blood pressure (BP) (19,33). Some recent studies report correlation among hypertension, salt sensitivity, and insulin resistance in obese humans (38), whereas others fail to observe a significant relationship (8). Animal models of obesity, hypertension, and insulin resistance display differences with respect to salt sensitivity. In Zucker rats, there is a clear correlation between salt intake and the severity of hypertension (4, 47), whereas in chronic hyperinsulinemic Sprague-Dawley (SD) rats, hypertension is not salt sensitive, albeit a shift in pressure-natriuresis relationship was reported (2). One important cont...

show abstract

Section: Discussionsupporting

confidence: 60%

Section: Discussionmentioning

confidence: 95%

Effect of salt on hypertension and oxidative stress in a rat model of diet-induced obesity

Dobrian

Schriver

Lynch

et al. 2003

American Journal of Physiology-Renal Physiology

View full text Add to dashboard Cite

show abstract

“…Diacylglycerol-stimulated PKC isoforms serine-phosphorylate IRS-1 and IRS-2, inactivating the downstream PI3-kinase needed for translocation of GLUT 4 to the cell membrane 34 . A high salt intake may enhance this mechanism because it results in a 33% increase in plasma free fatty acids 35 . Indirect effects of obesity may include activation of sympathetic nervous system activity 33 or inadequate suppression of aldosterone by salt 36 .…”

Section: Discussionmentioning

confidence: 99%

Differential Predictors of Insulin Resistance in Nondiabetic Salt-Resistant and Salt-Sensitive Subjects

Laffer

Elijovich

2013

Hypertension

View full text Add to dashboard Cite

We studied the characteristics of insulin resistance in 19 normotensive and 25 hypertensive subjects who underwent an acute protocol for determination of salt-sensitivity of blood pressure. Hypertensive subjects were older and more obese, with higher creatinine, lipids and aldosterone than normotensive volunteers. They also had higher glucose and insulin levels with a marked decrease in insulin sensitivity (HOMA2-S index). Once all participants were classified into salt-sensitive (SS) and salt-resistant (SR) groups, most of these differences were no longer present. In contrast, SS had classical characteristics of this phenotype (higher percentage of blacks, suppressed plasma renin, increased aldosterone-to-renin ratio and blunted renin and aldosterone responses to changes in salt balance). Despite similar insulin levels, HOMA2-S was significantly lower in SS than SR. Salt loading did not change HOMA2-S in SS or SR. In contrast, salt depletion, by significantly increasing glucose and insulin of SR, decreased their HOMA2-S to the levels observed in SS. Correlates of insulin resistance in SR included age, triglycerides, BMI, mean arterial pressure, aldosterone and epinephrine. However, only BMI and aldosterone remained as significant predictors in multivariate analyses. Correlates of insulin resistance in SS were mean arterial pressure, epinephrine and norepinephrine, all remaining as significant predictors in multivariate modeling. Our data confirm that salt sensitivity of blood pressure is associated with insulin resistance, suggest that salt restriction may be beneficial in SS but perhaps detrimental in SR subjects, and uncover possible differences in mechanisms of insulin resistance between SS and SR, with implications for pharmacological therapy.

show abstract

“…differences in feed intake or body weight. A strong direct effect of salt (dietary intake or infused) on insulin concentration has been reported in non-pregnant humans (Goodfriend et al, 1991) but the mechanism is not known. An earlier study with wethers found that plasma concentrations of insulin concentration decreased in wethers fed 20% NaCl for 14 days (Blache et al, 2007) and our results extend the work by Blache et al (2007) by showing a persistent (i.e.…”

Section: Discussionmentioning

confidence: 99%

Reproductive capacity of Merino ewes fed a high-salt diet

Digby

Masters

Blache

et al. 2008

Animal

View full text Add to dashboard Cite

An option to increase the productivity of saline land is to graze sheep on salt-tolerant plants, which, during the summer/ autumn period, can contain 20% to 25% of their dry matter as salt. This study assessed the impact of coping with high dietary salt loads on the reproductive performance of grazing ewes. From the time of artificial insemination until parturition, 2-year-old maiden Merino ewes were fed either a high-salt diet (NaCl 13% of dry matter) or control diet (NaCl 0.5% of dry matter). Pregnancy rates, lamb birth weights, milk composition and the plasma concentrations of hormones related to salt and water balance, and energy metabolism were measured. Leptin and insulin concentrations were lower (1.4 6 0.09 v. 1.5 6 0.12 ng/ml; (P , 0.05) and 7.2 6 0.55 v. 8.2 6 0.83 ng/ml; P , 0.02) in response to high-salt ingestion as was aldosterone concentration (27 6 2.7 v. 49 6 5.4 pg/ml; P , 0.05), presumably to achieve salt and water homeostasis. Arginine vasopressin concentration was not significantly affected by the diets, but plasma concentration of T 3 differed during gestation (P , 0.02), resulting in lower concentrations in the high-salt group in the first third of gestation (1.2 6 0.18 v. 1.3 6 0.14 pmol/ml) and higher concentrations in the final third of gestation (0.8 6 0.16 v. 0.6 6 0.06 pmol/ml). T 4 concentration was lower in ewes ingesting high salt for the first two-thirds of pregnancy (162 6 8.6 v. 212 6 13 ng/ml; P , 0.001). No substantial effects of high salt ingestion on pregnancy rates, lamb birth weights or milk composition were detected.Keywords: aldosterone, high salt, insulin, leptin, reproduction IntroductionSalinity is an increasing problem in agriculture worldwide (Ghassemi et al., 1995) and the use of halophytic plants such as saltbush represents one of the few options available to revegetate salinised landscapes and re-establish grazing systems . Some landholders in Australia are grazing sheep on saltbush to fill a summer/ autumn feed gap (Masters et al., 2006), a period that coincides with the greater demands of late pregnancy for autumn-or winter-lambing ewes. However, feeding saltbush may possibly have a negative impact on reproductive performance of the ewes as high salt intake may reduce intake and cause physiological changes associated with adaptation to the salt load.High salt intake has been shown to reduce voluntary feed intake (Masters et al., 2005;Blache et al., 2007) as well as the efficiency of energy use for production (Arieli et al., 1989) in sheep. A decrease either in voluntary feed intake or in fat reserves is usually associated with a decrease in the concentration of metabolic hormones such as insulin and leptin (Chilliard et al., 2005) and recently a high salt ingestion has been shown by Blache et al. (2007) to affect energy metabolism through changes in insulin concentrations in sheep fed high salt (20% NaCl) diets. Thus, the ingestion of large amount of salt may impact energy availability and consequently reproductive performance.There are also physiological 'con...

show abstract

Salt loads raise plasma fatty acids and lower insulin.

Cited by 24 publications

References 25 publications

Effect of salt on hypertension and oxidative stress in a rat model of diet-induced obesity

Effect of salt on hypertension and oxidative stress in a rat model of diet-induced obesity

Differential Predictors of Insulin Resistance in Nondiabetic Salt-Resistant and Salt-Sensitive Subjects

Reproductive capacity of Merino ewes fed a high-salt diet

Contact Info

Product

Resources

About