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Tziolas IM, Pikilidou MI, Zebekakis PE, Hadjistavri LS, Sarafidis PA, Lasaridis AN. Familial burden of hypertension and its effect on blood pressure levels, insulin resistance, and intracellular ions in Greek offspring. ACTA ACUST UNITED AC 2010; 3:141-9. [PMID: 20409954 DOI: 10.1016/j.jash.2008.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 10/03/2008] [Accepted: 10/07/2008] [Indexed: 10/21/2022]
Abstract
We examined the effect of familial burden of hypertension on blood pressure (BP) levels, insulin resistance (IR), and intracellular ions in healthy offspring of Greek families with one, two, or no hypertensive parents. A total of 118 adolescents and young adults were recruited. Three groups were formed: Group A, both parents were normotensive (N-N); Group B, one parent normotensive and one hypertensive (N-H); and Group C, both parents hypertensive (H-H). BP levels, homeostasis assessment model-IR (HOMA-IR) index, and intracellular Na(+), K(+), Ca(2+), and Mg(2+) were compared in the three groups. Also, multiple regression analyses were used to create models with BP parameters and HOMA-IR as dependent variables. Offspring of H-H parents had higher body mass index (BMI) (mean difference, 4.3 +/- 0.9 kg/m(2); 95% confidence interval [CI], 2.0-6.5), higher systolic blood pressure (SBP) (mean difference, 13.2 +/- 3.1 mm Hg; 95% CI, 5.8-20.7), increased levels of intraerythrocyte Ca(2+) (mean difference, 0.02 +/- 0.01 mmol/l; 95% CI, 0.05-0.1), and fasting blood glucose (mean difference, 0.31 +/- 0.10 mmol/l; 95% CI, 0.05-0.56) when compared with those with no parental history of hypertension. In the regression model, SBP was found to be significantly affected by BMI (beta = 0.43; P < .001), iK(+) (beta = -0.224; P < .01), and gender (beta = -0.298; P < .001). The addition of the parental history showed a significant independent association of H-H parental history with SBP (beta = 0.27; P < .05). HOMA-IR was significantly determined by BMI (beta = 0.511; P < .05), iNa(+) (beta = 0.211; P < .05), and iMg(2+) (beta = -0.205; P < .05). Parental history of hypertension did not influence the HOMA-IR index. This study highlights the relative importance and contribution of environmental and genetic influences on the development of high BP. Both these influences possibly alter the intracellular ionic environment. However, nurture rather than familial hypertension burden is the key factor of IR in Greek offspring.
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Affiliation(s)
- Ioannis M Tziolas
- Hypertension Unit, 1st Department of Medicine, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
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Iannello S, Milazzo P, Belfiore F. Animal and human tissue Na,K-ATPase in normal and insulin-resistant states: regulation, behaviour and interpretative hypothesis on NEFA effects. Obes Rev 2007; 8:231-51. [PMID: 17444965 DOI: 10.1111/j.1467-789x.2006.00276.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The sodium(Na)- and potassium(K)-activated adenosine-triphosphatase (Na,K-ATPase) is a membrane enzyme that energizes the Na-pump by hydrolysing adenosine triphosphate and wasting energy as heat, so playing a role in thermogenesis and energy balance. Na,K-ATPase regulation by insulin is controversial; in tissue of hyperglycemic-hyperinsulinemic ob/ob mice, we reported a reduction, whereas in streptozotocin-treated hypoinsulinemic-diabetic Swiss and ob/ob mice we found an increased activity, which is against a genetic defect and suggests a regulation by hyperinsulinemia. In human adipose tissue from obese patients, Na,K-ATPase activity was reduced and negatively correlated with body mass index, oral glucose tolerance test-insulinemic area and blood pressure. We hypothesized that obesity is associated with tissue Na,K-ATPase reduction, apparently linked to hyperinsulinemia, which may repress or inactivate the enzyme, thus opposing thyroid hormones and influencing thermogenesis and obesity development. Insulin action on Na,K-ATPase, in vivo, might be mediated by the high level of non-esterified fatty acids, which are circulating enzyme inhibitors and increase in obesity, diabetes and hypertension. In this paper, we analyse animal and human tissue Na,K-ATPase, its level, and its regulation and behaviour in some hyperinsulinemic and insulin-resistant states; moreover, we discuss the link of the enzyme with non-esterified fatty acids and attempt to interpret and organize in a coherent view the whole body of the exhaustive literature on this complicated topic.
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Affiliation(s)
- S Iannello
- Department of Medicina Interna e Patologie Sistemiche, University of Catania, Ospedale Garibaldi, Catania, Italy
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Taler SJ, Textor SC, Augustine JE. Resistant hypertension: comparing hemodynamic management to specialist care. Hypertension 2002; 39:982-8. [PMID: 12019280 DOI: 10.1161/01.hyp.0000016176.16042.2f] [Citation(s) in RCA: 205] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although resistant hypertension affects a minority of all hypertensives, this group continues to experience disproportionately high cardiovascular event rates despite newer antihypertensive agents. Hypertension represents an imbalance of hemodynamic forces within the circulation, usually characterized by elevated systemic vascular resistance. We studied the utility of serial hemodynamic parameters in the selection and titration of antihypertensive medication in resistant hypertensive patients using highly reproducible noninvasive measurements by thoracic bioimpedance. Resistant hypertension patients (n=104) were randomized to drug selection based either on serial hemodynamic (HD) measurements and a predefined algorithm or on drug selection directed by a hypertension specialist (SC) in a 3-month intensive treatment program. Blood pressure was lowered by intensified drug therapy in both treatment groups (169+/-3/87+/-2 to 139+/-2/72+/-1 mm Hg HD versus 173+/-3/91+/-2 to 147+/-2/79+/-1 mm Hg SC, P<0.01 for systolic and diastolic BP), using similar numbers and intensity of antihypertensive medications. Blood pressures were reduced further for those treated according to hemodynamic measurements, resulting in improved control rates (56% HD versus 33% SC controlled to </=140/90 mm Hg, P<0.05) and incremental reduction in systemic vascular resistance measurements. Although the number of patients taking diuretics did not differ between groups, final diuretic dosage was higher in the hemodynamic cohort. Our results demonstrate superior blood pressure control using a treatment algorithm and serial hemodynamic measurements compared with clinical judgment alone in a randomized prospective study. Our measurements of thoracic fluid volume support occult volume expansion as a mediator of antihypertensive drug resistance and use of impedance measurements to guide advancing diuretic dose and adjustment of multidrug antihypertensive treatment.
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Affiliation(s)
- Sandra J Taler
- Department of Medicine, Division of Hypertension and Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
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Wasada T, Kuroki H, Naruse M, Arii H, Maruyama A, Katsumori K, Saito S, Watanabe Y, Naruse K, Demura H. Insulin resistance is associated with high plasma ouabain-like immunoreactivity concentration in NIDDM. Diabetologia 1995; 38:792-7. [PMID: 7556980 DOI: 10.1007/s001250050354] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The aim of the present study was to elucidate the pathophysiologic significance of circulating ouabain as a link between insulin resistance (IR) and hypertension (HT) in NIDDM. Euglycaemic (4.5 mmol/l) hyperinsulinaemic (360-580 pmol/l) clamping was performed using an artificial endocrine pancreas. Plasma ouabain-like immunoreactivity (OLI) was determined by radioimmunoassay using a highly specific antibody to ouabain. HT was defined as systolic blood pressure > 140 mm Hg and/or diastolic > 90 mm Hg or being treated with antihypertensive agents. The values (mean +/- SEM) of glucose infusion rate (GIR) and plasma OLI were compared among the four groups classified using IR and HT as factors. Group I (IR-/HT-, n = 15): GIR 7.20 +/- 0.36 mg.kg-1.min-1, OLI 130.8 +/- 20.9 pmol/l, which was not different from that in eight normal control subjects (7.69 +/- 0.40 mg.kg-1.min-1 and 142.6 +/- 32.3 pmol/l, respectively); Group II (IR-/HT+, n = 13): 5.89 +/- 0.36 mg.kg-1.min-1, 172.5 +/- 35.0 pmol/l; Group III (IR+/HT-, n = 14) 1.91 +/- 0.28 mg.kg-1.min-1, 576.6 +/- 161.5 pmol/l (p < 0.01 vs Group I and II); Group IV (IR+/HT+, n = 15) 1.79 +/- 0.22 mg.kg-1.min-1, 703.1 +/- 170.1 pmol/l (p < 0.01 vs Group I and II), respectively. Six of 57 NIDDM patients studied exhibited very high (> 1500 pmol/l) plasma OLI concentrations, showed marked insulin resistance and were all hypertensive. When analysed as a whole, plasma OLI was negatively correlated with GIR (p < 0.001), but was not correlated with arterial blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T Wasada
- Diabetes Center, Tokyo Women's Medical College, Japan
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Gaboury CL, Simonson DC, Seely EW, Hollenberg NK, Williams GH. Relation of pressor responsiveness to angiotensin II and insulin resistance in hypertension. J Clin Invest 1994; 94:2295-300. [PMID: 7989585 PMCID: PMC330057 DOI: 10.1172/jci117593] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
To test the hypothesis that the hypertension associated with insulin resistance is secondary to an altered responsiveness of the vasculature to pressor agents, we evaluated the relationship between insulin resistance and pressor responses to angiotensin II (AII) in 21 hypertensive (HT) and 8 normotensive (NT) subjects on both a high (200 meq) and a low (10 meq) sodium diet. When sodium balance was achieved, each supine fasting subject underwent an AII infusion at a rate of 3 ng/kg per min for 60 min, with blood pressure monitored every 2 min. On the next day under similar conditions, a euglycemic hyperinsulinemic clamp was performed, with plasma glucose clamped at 90 mg/dl for 120 min. There was no significant relationship between the glucose disposal rate (M) or the insulin sensitivity index (M divided by the mean insulin level [M/I]) and blood pressure response to AII in the NTs, but a highly significant (P < 0.019) negative correlation (r = -0.55) in the HTs. Furthermore, in eight lean HTs whose body mass index was identical to that observed in the NTs, the relationship was even more striking (P < 0.008; r = -0.85). The results on high and low salt diets were similar; however, the M and M/I were significantly increased (P < 0.05) in the NTs but not HTs with sodium restriction. In conclusion, HTs but not NTs display a striking correlation between pressor response to AII and insulin resistance. This relationship is independent of the level of sodium intake. Furthermore, sodium intake modifies insulin sensitivity in NTs but not HTs. These results strongly suggest that a primary change in pressor response to vasoactive agents in insulin-resistant subjects can contribute to their elevated blood pressure.
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Affiliation(s)
- C L Gaboury
- Endocrine-Hypertension Division, Brigham and Women's Hospital, Boston, Massachusetts 02115
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Vettor R, Mazzonetto P, Macor C, Scandellari C, Federspil G. Effect of endogenous organic hyperinsulinaemia on blood pressure and serum triglycerides. Eur J Clin Invest 1994; 24:350-4. [PMID: 8088312 DOI: 10.1111/j.1365-2362.1994.tb01096.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hyperinsulinaemia and insulin resistance have been hypothesized to be the common pathophysiological factor of hypertension, NIDDM and obesity. To evaluate the possible role of hyperinsulinaemia and insulin resistance on hypertension, we studied a group of 37 patients with insulinoma who were admitted to our department in the period from 1966 to 1990. We recorded blood pressure and assayed blood glucose, plasma insulin, plasma triglycerides and serum uric acid levels, before and after surgery, in these patients and in a 37-subject control group. No significant increase in blood pressure and triglyceride plasma levels was recorded in the chronic hyperinsulinaemic hypoglycaemic patients, suggesting the lack of a direct role of hyperinsulinaemia on hypertension.
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Affiliation(s)
- R Vettor
- Institute of Semeiotica Medica, Patologia Medica III, University of Padua, Italy
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Affiliation(s)
- P E Pool
- North County Cardiology Research Laboratory, Encinitas, CA 92024
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Sharma AM, Schorr U, Distler A. Insulin resistance in young salt-sensitive normotensive subjects. Hypertension 1993; 21:273-9. [PMID: 8478036 DOI: 10.1161/01.hyp.21.3.273] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insulin resistance has been demonstrated in patients with essential hypertension, and insulin-mediated sodium retention is believed to contribute to hypertension in these individuals. Recently, a hyperinsulinemic response to an oral glucose load has been found in salt-sensitive normotensive subjects, suggesting that insulin resistance may be present in these hypertension-prone individuals before the development of hypertension. In the present study, we examined the relation between insulin sensitivity and blood pressure response to salt intake in young, lean normotensive subjects on a high and a low salt diet. Insulin sensitivity was estimated by the "insulin suppression test," i.e., by measuring the plasma glucose and insulin concentrations achieved during a 180-minute infusion of somatostatin, insulin, and glucose in 18 healthy male volunteers (age, 21-28 years) given a standardized low salt diet (20 mmol/day) for 2 weeks, supplemented by either 220 mmol of NaCl per day or placebo in a single-blind randomized order for 1 week each. We defined salt sensitivity as a significant decrease in mean arterial blood pressure (> 3 mm Hg [p < 0.05]) measured for 60 minutes at 1-minute intervals on the low salt diet. By this definition, seven of the 18 subjects were salt sensitive. Although insulin infusion resulted in similar plasma insulin levels (approximately 50 milliunits/L) in both groups, concomitant glucose infusion resulted in plasma glucose levels that were more than 50% higher in the salt-sensitive than in the salt-resistant group (p < 0.005 by two-way analysis of variance).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A M Sharma
- Department of Internal Medicine, Universitätsklinikum Steglitz, Free University of Berlin, FRG
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Salvetti A, Brogi G, Di Legge V, Bernini GP. The inter-relationship between insulin resistance and hypertension. Drugs 1993; 46 Suppl 2:149-59. [PMID: 7512468 DOI: 10.2165/00003495-199300462-00024] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Insulin resistance and compensatory hyperinsulinaemia commonly occur in patients with untreated essential hypertension. The coexistence of insulin resistance and hypertension can be viewed as a cause-effect relationship (insulin resistance as a cause of hypertension or vice versa) or as a noncausal association. Insulin can increase blood pressure via several mechanisms: increased renal sodium reabsorption, activation of the sympathetic nervous system, alteration of transmembrane ion transport, and hypertrophy of resistance vessels. Conversely, hypertension can cause insulin resistance by altering the delivery of insulin and glucose to skeletal muscle cells, resulting in impaired glucose uptake. For example, hypertension can impair vasodilation of skeletal muscle as a result of vascular structural changes and rarefaction, and increased response to vasoconstrictor stimuli. Also, the prevalence of muscle type 2b fibres (fast twitch fibres) may contribute to the development of insulin resistance. The common pathogenetic mechanism for both insulin resistance and hypertension could be activation of the sympathetic nervous system. This results in vasoconstriction, and may contribute to the genesis of vascular structural changes and increase the number of fast twitch fibres. Finally, hypertension and insulin resistance can be viewed as a noncausal association, according to the following hypotheses: 1) they may represent 2 independent consequences of the same metabolic disorder (intracellular free calcium accumulation), or 2) insulin resistance is a genetic marker and/or a pathogenetic mechanism of multiple metabolic abnormalities frequently associated with hypertension.
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Affiliation(s)
- A Salvetti
- Cattedra di Medicina Interna, University of Pisa, Italy
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Widgren BR, Herlitz H, Wikstrand J, Sjöström L, Berglund G, Andersson OK. Increased waist/hip ratio, metabolic disturbances, and family history of hypertension. Hypertension 1992; 20:563-8. [PMID: 1398891 DOI: 10.1161/01.hyp.20.4.563] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To test whether nonhypertensive subjects with a two-generation positive family history of hypertension (PFH) are characterized by disturbed glucose metabolism, 16 men (38 +/- 6 years old) with PFH and 25 subjects matched for age and with negative family histories of hypertension (NFH) were recruited. Blood pressure; serum lipids; erythrocyte transmembrane sodium transport; and the glucose, plasma insulin, and C-peptide responses to an oral glucose tolerance test were investigated. Subjects with PFH had higher blood pressure, body weight, body mass index (BMI), waist/hip ratio (WHR), and abdominal sagittal diameter than subjects with NFH. Baseline blood glucose, plasma insulin, serum lipids, and transmembrane sodium transport did not differ between the two groups. Blood glucose levels at 90 and 120 minutes after oral glucose were significantly higher in subjects with PFH than in controls. Blood glucose adjusted for BMI and WHR at 90 minutes was significantly related to a PFH. Plasma insulin level at 90 minutes during the glucose load was significantly higher in subjects with PFH. In multivariate analysis, WHR was significantly related to baseline blood pressure, insulin, and cholesterol, whereas BMI was significantly associated with the insulin response to the oral glucose tolerance test. Transmembrane sodium transport was significantly related to blood pressure only. In conclusion, subjects with PFH are characterized by increased body weight and BMI, increased visceral fat accumulation, and an altered blood glucose response to an oral glucose load. It was also shown that WHR was related to blood pressure and that BMI was more related to cholesterol and response to glucose loading than a PFH was.
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Affiliation(s)
- B R Widgren
- Department of Medicine, University of Göteborg, Sweden
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Sawicki PT, Heinemann L, Starke A, Berger M. Hyperinsulinaemia is not linked with blood pressure elevation in patients with insulinoma. Diabetologia 1992; 35:649-52. [PMID: 1644243 DOI: 10.1007/bf00400257] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have investigated the hypothesis that insulin is a causal and independent risk factor for blood pressure elevation in humans by comparing pre- and post-operative blood pressure values of 34 consecutive patients with histologically-confirmed diagnosis of insulinoma and 34 age- and sex-matched control patients. In patients with insulinoma hypoglycaemic symptoms were present for 18 (9-36) months. (Values are given as median and 95% confidence interval or mean and SD). After removal of insulinoma fasting plasma insulin levels decreased from 22 (16-28) mU/l to 11 (6-20) mU/l (p less than 0.003) and minimal fasting plasma glucose concentrations increased from 2.5 (2.0-3.0) to 4.4 (4.2-5.7) mmol/l (p less than 0.002) while blood pressure values remained unchanged. Body mass index before operation was comparable between the groups: 25.5 (5.4) kg/m2 in insulinoma patients and 24.8 (4.7) kg/m2 in control subjects. Pre-operative and post-operative blood pressure values did not differ between the groups, being (systolic/diastolic) 133 (18)/82 (9) mm Hg in insulinoma patients and 128 (15)/78 (10) mm Hg in control subjects before and 129 (19)/80 (10) mm Hg and 125 (11)/76 (7) after surgery. Chronic hyperinsulinaemia in patients with insulinoma is not associated with a detectable elevation of blood pressure values. Correction of hyperinsulinaemia after surgery for insulinoma does not result in blood pressure changes. These results argue against the hypothesis that insulin is an independent causal factor in the development of essential hypertension in humans.
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Affiliation(s)
- P T Sawicki
- Department of Nutrition and Metabolism (World Health Organisation Collaborating Centre for Diabetes), Heinrich-Heine University, Düsseldorf, FRG
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12
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Sowers JR. Insulin resistance, hyperinsulinemia, dyslipidemia, hypertension, and accelerated atherosclerosis. J Clin Pharmacol 1992; 32:529-35. [PMID: 1634639 DOI: 10.1177/009127009203200607] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Hypertension is only one component of a multifaceted metabolic-hemodynamic complex that also includes obesity, subtle and overt glucose intolerance, dyslipidemia, enhanced vascular resistance and accelerated atherosclerosis. Results of a number of studies in the past 5 years have shown that even nonobese, nondiabetic individuals with hypertension display insulin resistance, which is located in peripheral tissues (primarily skeletal muscle), is limited to nonoxidative pathways of glucose disposal, and appears to be directly correlated with the severity of hypertension. Insulin resistance and associated hyperinsulinemia in hypertensive individuals are also associated with increased plasma triglyceride levels and decreased high-density lipoprotein concentrations, which likely contributes to enhanced atherosclerosis. Hyperinsulinemia may directly promote atherosclerosis by enhancing LDL-cholesterol accumulation in vessel walls, vascular smooth muscle migration, and proliferation, augmenting connective tissue synthesis in the vascular wall, and decreasing the regression of lipid plaques. The enhanced peripheral vascular resistance that characterizes insulin resistance/hyperinsulinemic states may be related to decreased vascular smooth muscle responses to insulin, which normally modulates (attenuates) vascular contractile responses to vasoactive agents.
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Affiliation(s)
- J R Sowers
- Department of Endocrinology, Metabolism, and Hypertension, Wayne State University School of Medicine, Detroit, Michigan 48201
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Andronico G, Mulé G, Mangano MT, Piazza G, Donatelli M, Cerasola G, Bompiani GD. Insulin resistance and endogenous digoxin-like factor in obese hypertensive patients with glucose intolerance. Acta Diabetol 1992; 28:203-5. [PMID: 1315588 DOI: 10.1007/bf00778999] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Hypertensive obese subjects with glucose intolerance have hyperinsulinaemia, insulin resistance and intracellular cation imbalance resulting in increased sodium content. The aim of our study was to assess in these patients plasma levels of endogenous digoxin-like factor (EDLF), an inhibitor of the sodium-pump mechanism. We studied 14 hypertensive and 12 normotensive subjects with obesity and glucose intolerance for fasting blood glucose, and plasma insulin, C-peptide and EDLF levels: the two groups were matched for age and BMI and were studied after a 2-week wash-out period from hypotensive drugs. Compared with normotensives, hypertensive subjects had higher plasma insulin levels, a greater immunoreactive insulin/C-peptide ratio, a lower glucose/insulin ratio and higher plasma EDLF levels. Our results confirm that among obese people with glucose intolerance, hypertensives are more hyperinsulinaemic and insulin-resistant than normotensives and indicate that the intracellular cation imbalance in these patients may be attributable, at least in part, to EDLF.
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Affiliation(s)
- G Andronico
- Chair of Internal Medicine I, University of Palermo, Italy
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Modan M, Almog S, Fuchs Z, Chetrit A, Lusky A, Halkin H. Obesity, glucose intolerance, hyperinsulinemia, and response to antihypertensive drugs. Hypertension 1991; 17:565-73. [PMID: 2013483 DOI: 10.1161/01.hyp.17.4.565] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Responsiveness to antihypertensive medications was investigated cross-sectionally in 559 individuals comprising all treated hypertensive patients identified within a representative sample (n = 3,532, aged 40-70 years) of the Jewish population in Israel. A rate of dosage score (a summed ranking of dosages of all drugs taken) of two or more increased significantly with increasing levels of body mass index (BMI) from 37.5% in levels less than 23, 54.9% in levels 23.0-29.9, and 76.4% in levels of 30 or greater (p less than 0.0001). Multivariate analyses, adjusting for age, gender, arm circumference, and ethnic group, confirmed the independent effect of BMI on dosage score (p less than 0.001). At each level of dosage score, mean blood pressure levels were equivalent at all levels of BMI after adjusting for potential confounders. This indicates that achieved blood pressure level and not BMI itself was the main determinant of the higher dosing regimens prescribed at higher levels of BMI. In representative subgroups, glucose tolerance (n = 372) and hyperinsulinemia (n = 190) were determined and were found to be positively associated with a dosage score of two or more (p less than 0.05) independently of BMI. These effects could not be accounted for by poor compliance or by altered drug absorption or disposition since overnight urinary drug excretion and plasma drug concentrations 2 hours after ingestion, measured in 80 randomly selected patients from the study group, were not different across BMI categories at similar dosages.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M Modan
- Department of Clinical Epidemiology, Chaim Sheba Medical Center, Tel Hashomer, Israel
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Sechi LA, Melis A, Pala A, Marigliano A, Sechi G, Tedde R. Serum insulin, insulin sensitivity, and erythrocyte sodium metabolism in normotensive and essential hypertensive subjects with and without overweight. CLINICAL AND EXPERIMENTAL HYPERTENSION. PART A, THEORY AND PRACTICE 1991; 13:261-76. [PMID: 2065466 DOI: 10.3109/10641969109042062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Increased insulin circulating levels and perturbations of intracellular sodium metabolism have been reported in essential hypertensive patients, leading to postulate their involvement in the pathophysiology of the disease. In-vitro studies have shown that insulin modulates the activity of some transmembrane sodium transporters. The aim of this investigation was to assess in subjects with essential hypertension and/or overweight, the levels of fasting serum insulin, the activity of sodium transporters and their possible relationships. In 18 lean normotensive, 12 overweight normotensive, 18 untreated lean essential hypertensive, and 16 untreated overweight essential hypertensive subjects, we measured the fasting levels of blood glucose and serum insulin, and calculated the glucose/insulin ratio as an index of sensitivity to insulin. In addition, in the red blood cells of these subjects, we evaluated the maximal rate of ouabain-sensitive Na/K pump, furosemide-sensitive outward Na/K cotransport, Nai/Lio countertransport, and the constant rate of passive permeability to Na. When compared to lean normotensive, overweight normotensive, lean hypertensive, and overweight hypertensive subjects exhibited significantly higher fasting insulin levels, with lower glucose/insulin ratio. No significant difference was found in the activity of Na/K pump, Na/K cotransport, and passive permeability to Na. The Nai/Lio exchange was significantly increased in both hypertensive groups. Mean blood pressure correlated positively and independently with body mass index and fasting insulinemia, and inversely with the glucose/insulin ratio. No relationships were found between blood pressure, fasting insulin levels or glucose/insulin ratio and the activity of sodium transport systems. We conclude that hyperinsulinemia and insulin resistance are associated with essential hypertension independently of overweight. These data lend support to the hypothesis that insulin is involved, concurrently with other factors, in the pathogenesis of essential hypertension in both lean and obese subjects.
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Affiliation(s)
- L A Sechi
- Hypertension Unit, University of Sassari, Italy
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Nagi DK, Hendra TJ, Ryle AJ, Cooper TM, Temple RC, Clark PM, Schneider AE, Hales CN, Yudkin JS. The relationships of concentrations of insulin, intact proinsulin and 32-33 split proinsulin with cardiovascular risk factors in type 2 (non-insulin-dependent) diabetic subjects. Diabetologia 1990; 33:532-7. [PMID: 2253829 DOI: 10.1007/bf00404140] [Citation(s) in RCA: 150] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Standard radioimmunoassay for insulin may substantially overestimate levels of insulin because of cross-reaction with other insulin-like molecules. We have measured concentrations of insulin, intact proinsulin and 32-33 split proinsulin using two-site monoclonal antibody based immunoradiometric assays, and of insulin by a standard radioimmunoassay ("immunoreactive insulin") in 51 Type 2 (non-insulin-dependent) diabetic subjects in the fasting state. The relationships of these concentrations were sought with those of total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglyceride, plasminogen activator inhibitor, blood pressure, and indices of body fat distribution. Significant relationships were apparent between concentrations of "immunoreactive insulin" as measured by standard radioimmunoassay and triglyceride (rs = 0.42, p less than 0.001), total cholesterol (rs = 0.25, p = 0.038), high density lipoprotein cholesterol (rs = -0.30, p = 0.018) and body mass index (rs = 0.30, p = 0.017), but only the relationships with triglyceride (rs = 0.36, p = 0.006) and body mass index (rs = 0.26, p = 0.34) remained significant when concentrations of immunoradiometrically measured insulin were employed. Concentrations of 32-33 split proinsulin, which comprises the major insulin-like molecule in these subjects, correlated positively with triglyceride (rs = 0.33, p = 0.009), total cholesterol (rs = 0.23, p = 0.050), and plasminogen activator inhibitor (rs = 0.26, p = 0.049), and negatively with high density lipoprotein cholesterol (rs = -0.29, p = 0.021).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D K Nagi
- Department of Medicine, University College and Middlesex School of Medicine, Whittington Hospital, UK
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19
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Abstract
The author has reviewed the development of the concept that insulin resistance is related not only to the hypertensive state but potentially to the initiation and maintenance of high blood pressure. Potential sequelae of insulin resistance and hyperinsulinemia, as they apply to atherogenesis, are also discussed. The impact of present antihypertensive pharmacologic therapy on insulin resistance is addressed, as are future directions in pharmacologic and nonpharmacologic management of hypertension. In addition, the author speculates on possible mechanisms leading to insulin resistance in hypertension.
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Affiliation(s)
- A Swislocki
- Medical Service, Martinez VA Medical Center, CA 94553
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20
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Grimaldi A, Sachon C, Bosquet F, Doumith R. [Intolerance to carbohydrates: the seven questions]. Rev Med Interne 1990; 11:297-307. [PMID: 2096435 DOI: 10.1016/s0248-8663(05)80862-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The borderline between diabetes and intolerance to carbohydrates has been drawn on the basis of prospective studies which determined a glycaemic threshold marking the risk for microangiopathy. On the other hand, the borderline between intolerance to carbohydrates and normal glucose tolerance remains arbitrary: 25% for subjects who are intolerant to carbohydrates return to normal glucose tolerance within 10 years. This is due to the fact that intolerance to carbohydrates is a heterogeneous entity which should be dismembered according to the severity of insulin deficiency and to the degree of insulin resistance. Alteration of insulin secretion is perhaps the most specific marker of susceptibility to non insulin dependent diabetes, but insulin resistance is certainly the principal factor exhausting insulin secretion and leading to non insulin dependent diabetes. Insulin resistance and the hyperinsulinism it creates seem to facilitate atherogenesis, even when glucose tolerance is still normal, so that the oral glucose tolerance test is not only poorly reproducible but loses a great deal of its value in the early detection of vascular risk. Measurements of fasting and post-prandial glucose levels and of A1C haemoglobin, cholesterol, triglyceride, and HDL cholesterol levels usually make it possible to classify subjects into one of the three following categories: (1) no risk of macro- or microangiopathy; (2) diabetes with a risk of macro- or microangiopathy; (3) intolerance to glucose with risk of atherogenesis but no risk of microangiopathy. The oral glucose tolerance test probably remains useful within a small set of values that are either very slightly above normal or dissociated. Measuring blood insulin levels might be a better way of assessing the risk of atherogenesis, but the clinical use of this test requires evaluation.
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Affiliation(s)
- A Grimaldi
- Service de diabétologie, CHU, Pitié-Salpêtrière, Paris
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22
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Abstract
Diabetes mellitus and hypertension are both common diseases, especially with an increasingly aged population. Hypertension accelerates the development of diabetic retinopathy, nephropathy, and peripheral vascular disease in the diabetic patient. Diabetes represents a type of premature aging and hypertension in the diabetic patient is characterized by many of the same pathophysiologic properties seen in the elderly hypertensive patient.
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Affiliation(s)
- J R Sowers
- Division of Endocrinology, Wayne State University, School of Medicine, Detroit, Michigan
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