Insulin resistance and hypertension in lean postmenopausal women.

AJH-APRIL 1999-VOL. 12, NO. 4, PART 2

POSTERS:

Obesity,

Insulin

Resistance,

and

Diabetes

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I026

INSULIN RESISTANCE AND HYPERTENSION IN LEAN POSTMENOPAUSAL WOMEN. ~.A. Feidstein*, A. Renanld, Y~ Cauterucci, M. Akopinn, M. C a l c a p o and D. Garrido. Hypertension Program, Hospital de Clinieas San Martin Bnenus Aires School of Medicine and Health Sciences Inetitnte School o f Medicine (Barcelo Foundation). Rivadavia 4243, 6° B (1205), Buenos Aires, Argentina. The aim of the study was to elucidate the role of hyperinsulinemla rmaalin resi~mce in hypertension of lean postmeanpausal women. Twentyfour women with essential hypertemsian (systolic/diastolic >140/90 mm Hg) and • body mass index (BMI) less than 26 kg/mz not receiving antlhyperteasive treatment or who had been without treatment for • 4-wesk washout period, and 10 normotcasive postmenopansal weight- and agedmatched controls were compared. Both grenl~ were not receiving hormone replacement therapy. Hip and waist circumferences were measured and waist/hip ratios were calculated. Casual blood pressure was measured in triplicate. Neither the fasting plasma glucose nor serum imufin levels in hypertensive women and normotanslves differed significantly.During 2h oral glucme (75 gFtoinrnaco test the mean plasma gl-ocose lereb after 30 rain (172.5 + 40.24 mg/dl versnc 143.67 ± 20.16 nlg/dl), 60 rain (134.88 ± 38.78 mg/dl w~as 112.33 ± 5.44 mg/dl) and 120 rain (116.08 ± 26.65 mlg/dlversus 9S.56~20.17 mg/dl) were significautly higher in hypertemives than that for normoteasDes(P ~0.0~ for all three comparlsom). The mean seram insulin leveh of hypertensive woman were significandy higher than that in normutansives after 15 min (92.04 ± 59.90 pUhnL versus 54J~9 ± 33.67 pU/mL) and 17.0 rain (49.63~44.4.5 p.U/mL versus 19.22+24.10 ttUhnL; P<0.05 for both comparlsom). The mean ~xmn insulia: plasma glucose ratio for hypertensive women was s i ~ u t l y higher than that for anrmotemlves after 15 rain (0.596 ± 0.46 versus 0 ~ . 2 0 pU/mg), 60 mill (0.406 ± 0.30 versus 0.329~ 0.25 pU/mg) and 120 rain (0.436 + 0.35 versus 0.20~ ± 0.26 ~.U/mg) (P
HANDGRIP TEST AS A TOOL TO ASSESS MODIFICATIONS IN AUTONOMIC CONTROL OF HEART RATE AT ESSENTIAL HYPERTENSION D.Voita*, V.Mackevics', A.Vitols ° Latvia Institute of Cardiology, "Latvia Academy of Medicine,Riga,Latvia. Impairement of autonomic nervous activity has been recognized in diabetes mellitus and essential hypertension (EH), but there is little knowledge about possible modifications in autonomic activity at EH with non-insuline dependent diabetes mellitus (NIDDM). The aim of study vms to evaluate whether the autonomic control of the sinus node differs in EH pts with NIDDM and EH pts without glucose metabolism disturbances. On 13 EH pts with NIDDM (group A; men, 63±1.8 yrs aged, HbAI= 9.3±0.2%, ranged 8.7-10.2%),17 EH pts without metabolic features of insulin resistance syndrome (group B; gender, age and blood pressure matched) and 19 controls (group C; gender and age matched) the heart rate (HR) and finger mean arterial pressure (MAP) were monitored non-invasively and bradycardic reaction to baroreceptor reflex (BR) activation by neck suction was evaluated at rest, dudng handgdp (HG, for 60s with force 50% of maximal) and following artenal occlussion (AO). All antihypertensive medications if any had, were discontinuated 2 weeks before the study. At rest in groups A, B and C the MAP wero 110+_2.6 vs. 109~ :f.2..6 vs. 90i1.4 mmHg, respectively. Group A compenng to groups B and C was characterized by increased HR (80+_2 vs. 72:t:3 vs. 70~3 bpm; P <0.05) and decreased bradycardic reaction to BR activation (1.9-~-0.3vs. 4.~0.9 vs.lOi-O.6 bpm; P<0.05). At HG cessation moment the amplitude of pressor reaction (PR) was similar in all groups (29J:5 vs. 29-~. vs. 26-22 mmHg), but HR acceleration was decreased in group A companng to groups B and C (12.2±2 vs. 24.+.2vs. 18±.2 bpm; p<0,05), as well as smaller pert of PR amplitude wes supported by postexercise AO (35~:8% vs. 58:L6 % VS. 54±3; P <0.05). Thereby, in EH pts with NIDDM observed modifications in BR bradycardic reaction and HR acceleration dudng HG suggest about most expressed changes in vagal control of sinus node as well as in alterations of sympathetic outflow related with activation of Ill-IV groups afferents dunng PR supported by bostexercise AO. Thus. handgdp test is useful iD~,s~,~%~0.ent the autonomic control modifications. hypertension, insuline resistance, baroreflex, autonomic nervous system.

Key Words:

hyperimolincmla~nwlin resistance~ ambulatory blood pressure, postmmopaasal women.

1027

I028

HYPERTENSION AND OBESITY. INFLUENCE OF LIFE STYLE MODIFICATIONS ILM. Santos, M.E.Macedo*, A.Monteieo*, J. Freitas, C.Marujo, A.Falcio de Freitas Servif6 de Med 2 and Oporto School of Medicine-Hospital de SAo J o i o - Porto - Portugal Obesity is a chronic, multifaetorial disease where genetic, behavioral and environmental factors are connected. Nutritional deviation is common in western countries and plays an important role on the genesis of several cardiovascular risk factors. Aim: to evaluate the effects of low caloric diet and aerobic exercise on blood pressure, on the waist-to-hip circumference (W/H) ratio and weight reduction. Patients and methods: two hundred and twenty five patients with hypertension (60 males, aged 51(10) years and 165 women, aged 49(12) years) were studied. FLqy-four were overweight (2530 Ks/m:). All padents were submitted to a nutritional questionnatre 24 hours before evaluation. Supine BP and anthropometric parameters were measured before prescription a low caloric diet adjusted to age, gender, physical activity and professional lifestyle. Implemematiou of aerobic exercise was also performed. Mean duration of follow-up was 36(8) months. The patients were observed each 4 months for BP evaluation, anthropometric measurements and diet adjustments. During follow-up there were no changes on antibypertensive d~ug therapy, and salt intake. Results:

OBESITY, HIGH BLOOD PRESSURE AND AUTONOMIC NERVOUS SYSTEM. RM Santos, J Freitas, MJ Carvalho, ME Macedu*, A FalcAo de Freitas Centre de Estudos da Fun~o Auton6mica - Hospital de S~o Jo[Io Porto: Faculdade de Medicina do Porto: Portugal

tat evaluatinn last e~luaUon

WelgM(Iqg) BMI(ks/m2 ) W/H 84.3(12.6) 33,3(4.4) 0.901(0.08) 78.9(11.3) 31.9(3.3) 0.g71(0.06)

p

0.003

• Wet~ght(Iqg) 2$30 -4.8(4.9) p 0.O4

0.02

0.01

&~Ml(ks/m2 ) • W/H -0.7(I.4) -0.007(0.03) -L9(2,0) -0.012(0.03) 0.02 m

SBP(mmHs) 157.0(22~6) 139.1(18.4)

DBP(mmH~ 911.1(13.2) 118:4(14.4)

0.0001

.0.0001

ASBP (mmHI0 ADBP (mmHl~ -22.5(15.3) -13.0(14.4) - 1L0(TA.0) -|.1(I 7.0) ns ns

Conclusions: Dietary intervention and aerobic exercise induced a significant decrease in BP, BMI and W/H ratio. BP reduction was similar in overweight and obese patients. A significant reduction hi BP can be achieved with even small reductions in weight.

Key Words: Obesity, Weight, BMI, Waist-to-hip circumference ratio, Blood pressure

Aim: Assessmout of relationships between obesity, high blood pressure and autonomic nervous system. Population: 14 overweight (BMI>25Kg/m 2) with hypertension and 10 lean and also with hypertension, aged-matched. 11 overweight (BMI>25Kg/m 2) normotensiv¢ with 23 lean and also normotensive. Methods: We continuously digit~e with a sample rate of 300 Hz/channel, the non-mvusive digital arterial pressure wave (Fianwes) and the ECG. We use FFT for spectral analysis of RR interval and systolic blood pressure variabili~-. Baroreceptor spontaneous gain was obtained by 2 methods: cross spectral coherence of the LF band, above 50% or ¢ index - BRG~ and by the analysis of linear regression of temporal sequences - BRGt. Hemodynamic ly,u'ametars (CO and TPR) were calculated non-invasively by the"TNO~ modolflow" analysis of the finawes arterial wave. Remits: ~ertensive Normotensive CO SV TPR FIR SBP DBP HRV (an)

1MC>25 5.S2~I.S)* 75.7(15,4)* 1554~642)* 70.4~11.2) 151,5(12.51 94.~7.5) 49.5(13.2)

1MC<25 4.1 ~1.5) 52.2~11.3) 2760~1504~ g2.1(22.0~ 164.1(29.8) 99.3Q 5.9) 3g.3(16.t)

IMC>25 5.56{1.31 73.7~12.6) 1250(431)i 79.~11.7~ 121.7(16.71 69.3~6.6) 42.1(I LS]

E~4C<25 5.390.0 ) 7L0(14.4 I 1371(329.0) 77.5~10.5I 126.0(12.1} 6g 9~10.0) 45.2(17.0)

SBPV 5.94~3.$) 9A~9,25) 4.g6(4.7) ! 5.10(3.7) LF~BP). BR $.0(3.7) ?.0(8.3) 13.1(S.7) 16.5(g.41 Avmase (sd) *p<0.05; **p<0.0l; ***p<0,001, Units: HR in bpm; CO in L/I~ SV in ml; I~.V i= ~ 2 ; SBPV in mollS2; BR em ms/mml~ TPR in dyu.s.~m-5; SBP trod DBP in mmHg.

p*<0.001 Conclusion: Hypertension in obese seems to be related to cardiac output. In the lean population high blood pressure is probably" due to the higher total ~ripherical resistance and a tendency to high sympathetic predominance. In normetensive subjects the autonomic Ka~devhemodynamic profile are similar between obese and lean.

Woros:

O~esity; Hypertension; sympathetic

73A