The effect of dietary patterns on ambulatory blood pressure (ABP): The DASH study

A[H-APRfL 1997-VOL. 10, NO. 4, PART 2

INFLUENCE OF RACE AND DIETARY SALT ON BLOOD PRESSURE (BP) RESPONSES IN SAL,T SENSITIVE HYPERTENSIVE, M.R. Web*. A. Weder*, for the MIST Study Group. Universityof MarylamlSchool Of Medicine,Baltimore,MD. University olMichigan Medical Center, Ann Arbor, Ml.

In order to elucidate possible racial differences and the importanceof salt restrictionas part of the antlhypetiensiveregimen, we performed a randomized, double.blind, placebo-controlled, parallel-group comparison of the antihypertensive effect of an ACE inhibitor (enalapril (EN) 5 or 20 mg b.i.d.) or a calcium antagonist

(isradipine(lSR) 5 or 10 mg b.i.d.) during high and low salt inrskes. Our patients (Afri.an-Americans (AA), n=96, Hispsnic (H), n=63, Caucasian (C), n=232) were preselected for salt sensitivity (>5 mmHg increase in diastolic blood pressure (BP) going from low to high salt diet) and for having Stage I Stage III hypetiensionbased Cmtheir ad Iihitumsalt diet prior to study entry, Althoughduring the high salt diet (314.7 + 107.5mmol urine Na’/day) there was greater blood pressurereductionwith both EN and ISR comparedto low sah diet (90. I f 50.8 mmol Na”/day), the absolute BP acbieved in all races was consistently lower on low salt diet irrespective of antihypemensiveagentused. However, AA, C, H. lSR-treated saltsensitive hypertensive demonstrated a smaller difference between high and low sah diets (AA -3.6/-1.6mmHg, C -6.2/-3.9 mmkig,H S.1/-5.3 lmmHg)than En-treated padents (AA -9.0/-5.3 mmHg, C I I.8/-7.0mmHg, H -11.1/-5.6mmHg). On low salt diet, AA, C, and H had similar BP controlwith En and ISR. However,on high salt diet, AA had better BP contrnl with ISR compared 10 EN, wherein tbere was no dit~erencebetweenthe drugs in C and H. We conclude that dietary salt reduction helps reduce BP in salt-sensitive hypertensiveAA, C, snd H treated with En or JSR. In this study, rsce-related differencesin antihypertensiveresponses to EN andISR persistdespitecontrol(or preelection)for saltsensitivity. KeyWords;

salt, salt sensitivity,race,drugtherapy

ORALS: Nutrition

CHANGES IN SYMPATHETIC ACTIVITY AND INSULIN SENSITIVITY DURING BODY WEIGHT REDUCTION IN OBESE SUBJECTS K Masuo*, H Mikami* and T Ogihara*. Osaka University Medical School, Osaka, Japan. To evaluate theeffectsof body weight reduction(BW-red)on

sympatheticactivity and insulin(lNS) sensitivity. In 20 obese NT(at entry; 43~2yrs,S3kg,28.7~1.2kg/m2), 19 obese HT (43~3,B4,z3.7~1.3)and S non-obese NT(43~2~6S,23.5~1.l ), INS. norepinephrlne (NE) were BP, blood glucose, measured hefore and every 30 min for 2 hra after 75g omt glucoseload at entry,at 1 month and 3 monthswith low caloric (1000kcal,7gNaC1/dey)diet. Similar degree of BW-red, as 4kg/lmth(l.4kg/m2) and Skg/3mths(2.7kg/m2) were recognized in obese NT and obeae HT. Fasting BG, INS, NE and

AUCSof BG, INS, NE in obese HT at entry were greater than in obeseNT (AUC of BG; P<.05, A(JC of INS: P< .01, AUC of NE;,P<.05). After 1 month’s BW-red, AUC of BG & AUC of NE m obeseHT decreasedsignificantlycomparadto those at entry, however,BPs and AUC of INS did not decrease.After 3 months, BPs, fasting INS & AUC of INS decreased significantly in obeseHT. While, in obese NT, BPs, AUC of BG, AUC of NE and AUC of INS decreased after 1 month’s BW-redandbecsme similarto the values in non-obeseNT. The %decrementin AUCof NE in obeseHI’ at month-1 was similar to tbat in obeseNT at month-t, and %decrementinAUC of INS in obese H’f at month-3 was similar to that in obese NT at month-1.The %decrement of AUC of NE at month-f &-3 in obese subjects(NT+HT) correlated with %red bt BW(PCO.01) and %red in BP(P< 0.05), but %decrements in AUC of INS didn’t correlate with %red in BP or %red in BW. The

sympathetic responsiveness(mex NE/basal NE) and INS responsiveness increased with reducing BMI in HT These resnlcs demonstrated that BW reduefioss improvedsympathetichyperactivityprecedingBP reductionand hyperinstdinettsiain obese HT. and that these mechanisms in BP-redwith BW-redin obese WI’appearedto be differentfrom those in obese NT. significantly.

KeyWords:

sympathetic nerve activity, inaulin sensitivity,

obesity.

LOCALINSULIN tNOUCES PAI-I RELEAsEAND REtAXESFOREARM ARISRtOLES INNORMAL SUBJSCTS. F. CARMAS S1’,M. htoRAL#,F. DE NEQRI’,L. FERFNNI’, M. FERDEGHIN?, G, DELL’OMO’, R. PEDRINELLI’. ClinicsMedics’,MedicineNucfaere’,UnlversitAdi Piss, Ilsly BMKGMMD: Both PAI-I arid insulin (INS) Isveks ara frequentlyinereesed in hypertensivesubjects in the contexl of ths ayndromeX. Still, ths exact retstionshipbetween the two parametersis incompletelyctadfied./rr-vlru experimentssuggest a dir-t sction of INS on endothelial PAI-1 release, bul the evkiencafor eucha mdwdem in man is still missing.ME3BQES: INS was irrfueedinto the right brechielartery of 8 young nermsl malefastedvotuntaars(28*3 yrs)at ratescslcubted to raiselocal mrtcenttstioneto the physiologicalpoefprandislhyperinsulinemic range. Infusionlasted 2 hours preeededand fol!owedby 30-min saline.Arterial(A) and deepvein (V) blondsamplesfor INS (RIA), glwosw (GLUC,gltseooxidsse)and PAI-1 antigen (ELISA) were collectedhseslly and every 30 minutes thereafter to deriie A-V ftow (FBF, venoue differemee [A,V..J. Forsarm H plethysmogrsphy)was measuredat the same intervalsto derive net metabolic!fAertcea [BAL,(V-A) x FBF].SE.8UH8(maane+SD or medians & range for skewed data): Local INS infueton inereaeadINS%) from -1,2 (-7.9/5.6) to 73 (37/190) and 54 (2.W140)@J/ret at 80 and 120 minutes reepactivefy, and, corteapondingty,stimutstedGLUC uptake (from 17+13to 38*I9 and 44w1 m~min x dr’, pc.Wl w baseline). FBF wee slill unchangedat 80 min (baseline:2.7+.6w 3.3+.6mtlminx dt’), htd ineraaeed sfesdity afterwards, averaging 4.*.6 m~min x dr’ (K.WI W hsaafitse)after 120 min infusion. FBF wee stffl higher than at bssefinain the pst-infusicm period (3.6 +.7, p<.01)when INS~.)[0.3@/2) @J/m~hsdfully recovered.PAI-I BALincreased front 2.1 (-1/13)to 23.2 (-.8/108)n@minx all”’(pd2) after W min of INS perfueton, i.e. at a time whan FBF wee stable, and normalized30 min after INS was stepped[4.3 (-12 /72) ts@minx all”’] ~: INS efirnufstesPAI-1 retesse front foresmt Vessefsof notrnslautsjaefswtfha time SDUrSe indapendantof any lNS-trtw3isWdveeornotw affect. Futthertrwre, in emntrssfwkh prevtouestaternenfa, focalINS infusionretexesforearmatterieles Kaywords: SSSULNS, PAt-\,VASOSEO noN, Ssmolnawu

THE EFFECT OF DIETARY PATTERNS ON AMBULATORY BLOOD PRESSURE (ABP): THE DASH STUDY. TJ Moore*, ~ -, LJ Appel, W?dVollmer, D SimonS-Morton, D Harsha, FM Sacks. Brigham end Womens Hoepitad,Boston, MA

The DietstyApproachesto StopHypertensionstudy(DASH)was a multieantar,rendomizad,faedingstudythat assessadthe BPeffect of diet in adultswith SBP<160and DBP80-95mmHg. After a 3weekrun-inperiod,subjectswere rsndomuedto Iof 3 intervention dietsfor8 wesks:CONTROL(similarto typicalAmeriesnintake);a diat like CONROLbut richin fruitaand vegetables(FfV);and a diet rich in fruits,vagetsbles,and dairj produetsbut reducedin fat (COMBINATION).In 354eubjeets,we measuredABP every20 min(Spaeelabs90207)for 24 hoursbeforeand afterthe B-wsak intewentionfeadingto aeeesathe BPeffactof the diets duringthe total24-hourperiod,day (7am-l lpm), and night(llpm-7am). Standardcuff BPwasalso meaeuredon 5-7 differentdayeat the startandend of the 8 waakfeeding(SPHYG)to mmpara against ABPMchanges.The BPchangesin the ConfmlDietgroupwere
19A