Cardiovascular responses to physical and psychological stress in female alcoholics with transitory hypertension after early abstinence

BACKGROUND

Male alcoholic patients with acute withdrawal hypertension have shown exaggerated cardiovascular reactivity to stress after 3 to 4 weeks of abstinence, although resting blood pressures (BP) had returned to normal. Studies of this nature, however, have not been extended to women.

METHODS

In this study, 32 alcohol-dependent women, abstinent for 4 weeks, were compared with 16 healthy controls on cardiovascular hemodynamics during rest and in response to 2 moderately aversive stressors: isometric handgrip and a speech task. The alcoholics were placed according to withdrawal BP into transitory hypertensive (tHT; n = 16; BP >or=140/90 mm Hg) and normotensive (NT; n = 16; BP <140/90 mm Hg) subgroups.

RESULTS

During stress testing, the transitory hypertensive women had increased diastolic BP (p < 0.01), a higher peripheral resistance index (p < 0.05), and a reduced cardiac efficiency index (p < 0.03) relative to the normotensive and control subjects.

CONCLUSIONS

This cardiovascular pattern suggests that both cardiac and vascular functions were altered adversely in the transitory hypertensives. In contrast to men examined in previous studies, the transitory hypertensive women had no exaggeration of BP reactivity, but instead showed sustained alterations of resting cardiovascular function in relation to chronic alcohol consumption. Although the pattern of cardiovascular dysregulation seems to be different in female alcoholics than in males, it is consistent with studies showing that cardiovascular effects in women are more severe than in men and emerge at a lower threshold level of chronic drinking.

Cardiovascular effects of alcohol

The ingestion of one or two alcoholic drinks can affect heart rate, blood pressure, cardiac output, myocardial contractility, and regional blood flow. These actions generally are not clinically important. In the presence of cardiovascular disease, however, even such small quantities of alcohol might result in transient unfavorable hemodynamic changes. Moreover, alcohol abuse can produce cardiac arrhythmias, hypertension, cardiomyopathy, stroke, and even sudden death. In contrast, moderate alcohol use produces changes that have an overall favorable effect on atherosclerotic-related vascular diseases. Because cardiovascular disease due to atherosclerosis is the leading cause of death in Western society, this desirable effect of alcohol use outweighs its detrimental actions, resulting in favorable findings in population studies. Nevertheless, the body of evidence argues against encouraging alcohol use for its cardiovascular effects.

Drinking history is related to persistent blood pressure dysregulation in postwithdrawal alcoholics

We have previously demonstrated that alcoholics with transitory (< 72 hr) elevations in blood pressure (BP) during withdrawal continue to show residual cardiovascular dysregulation up to 4 weeks of abstinence. The present study replicates and extends these findings. Alcoholic inpatients were divided into three subgroups (ns = 14) based on BP during the first 72 hr of withdrawal: transitory hypertensives (tHTs; BP > 160/95 mm Hg), transitory borderline hypertensives (tBHs; 140/90 < or = BP < 160/95), and normotensives (NTs; all BPs < 140/90). All patients had normal resting pressures after 72 hr of withdrawal. At 3-4 weeks postadmission, the alcoholics and 14 nonalcoholic controls (CONTs) were tested at rest and during a 5-min handgrip task. The tHTs showed an exaggerated systolic and diastolic BP response to handgrip compared with NTs and CONTs, with tBHs intermediate (ps < 0.05). Drinking history showed the tHTs had the highest reported level of alcohol consumption and severity of withdrawal symptoms (ps < 0.05). Regression analyses indicated that consumption of hard liquor was the variable most predictive of admission BPs; further, parental history of hypertension potentiated this relationship for systolic BP. Age and consumption of nicotine and caffeine were not significant predictors of admission BP. The results suggest a persistent cardiovascular dysregulation in alcoholics showing transient hypertensive withdrawal BPs. These alcoholics may be at increased risk for future alcohol-related cardiovascular disorder.

Plasma [3H]-noradrenaline kinetics and blood pressure following regular, moderate ethanol consumption

Normotensive male volunteers (n = 8) either abstained from ethanol for 4 days or consumed 66 g of ethanol per day in an open, crossed, random order study. Mean arterial pressures rose by an average of 5.4 mmHg following the ethanol phase of the study (P less than 0.001). Plasma noradrenaline (NA) concentration was higher during ethanol ingestion (P less than 0.01), principally because of a significant reduction in NA clearance of -1.51 l min-1 m-2 (P less than 0.05). In contrast, NA spillover or release rates did not significantly differ between the two study periods. Total plasma calcium levels were significantly lower (P less than 0.05) following the ethanol compared to the control period. These data do not appear to support the proposition that regular alcohol consumption raises blood pressure by producing a generalised increase in sympathetic activity.

Decreased vascular responsiveness to noradrenaline following regular ethanol consumption

Ten normal volunteers consumed 80 g of ethanol per day or abstained from ethanol for 4 consecutive days prior to measurements of blood pressure, heart rate, vascular responsiveness to noradrenaline (NA) and angiotensin II (AII) infusions and sympathetic responsiveness to isometric handgrip exercise in an open, random order, crossed study. Supine systolic and diastolic pressures and heart rates, and erect systolic pressures rose significantly following ethanol. Vascular responsiveness to NA infusions was reduced in all subjects following ethanol, while responses to AII infusions did not show a consistent pattern of change. Plasma renin activity, plasma NA and adrenaline concentrations, and concentrations of the NA metabolite 3,4 dihydroxyphenylethylene glycol (DHPG) did not significantly differ following ethanol and control treatments. The rise in plasma NA following 2 min isometric handgrip at 50% of maximal effort was greater following ethanol (0.24 +/- 0.21 nM) than control (0.12 +/- 0.10 nM) but the difference did not reach statistical significance. The pressor effect of regular ethanol consumption and the reduced vascular reactivity to NA may both be the result of an increase in sympathetic activity that was not large enough to measurably alter resting plasma NA concentrations.

The effects of alcohol on blood pressure and electrolytes

The interaction between alcohol abuse, changes in blood pressure, and electrolyte abnormalities is complex. Some effects of alcohol are seen only with acute ingestion, some during withdrawal, and some only in chronic drinkers. Careful attention to the interactions between the metabolism of various electrolytes can prevent unnecessary morbidity and mortality in alcoholic patients.

The effects of alcohol on the endocrine system

Male hypogonadism is the best documented endocrine effect of chronic alcoholism. A reversible clinical syndrome resembling Cushing's syndrome has also recently been described in some chronic alcoholics. The pituitary-thyroid axis is relatively resistant to the effects of ethanol, although mild abnormalities in various thyroid tests are frequently noted in the presence of alcoholic liver disease.