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Systemic Hemodynamic Changes in Older Hypertensive Patients After Drinking Water or Eating a Meal.

Sebastião Rodrigues Ferreira-Filho*
Flávio de Castro Rodrigues Ferreira
Paulo César Oliveira
Marcio Nery

(*): Serviço de Nefrologia da Universidade Federal de Uberlandia, MG. Brazil.

Correspondence to Sebastião Rodrigues Ferreira Filho, Federal University of Uberlândia, MG, Brazil. Av. Pará No. 1720, Bloco 2H sala 1, Campus Umuarama,Uberlândia, MG, Brazil, Zip Code: 38405-382. Phone: 55-034-3211-8545; Fax: 55-034-3211-9560; E-mail: srff@triang.com.br

Systemic Hemodynamic Changes in Older Hypertensive Patients After Drinking Water or Eating a Meal
Hypertension published February 26, 2007, 10.1161/HYPERTENSIONAHA.107.087809nsion

Abstract

Elderly hypertensive patients can have their blood pressure levels modified after drinking water or eating a meal. We studied the alterations in the systolic function of the heart in 17 patients (65 to 79 years old, 10 males and 7 females). After overnight fasting, they received 500 ml of oral water or a meal of 700 kcal. We estimated the cardiac systolic function at the end of fasting time and for 60 minutes after the ingestion of food or water. The thoracic impedance, a non invasive method, was utilized to measure the cardiac output (CO), stroke volume (SV) and total peripheral resistance (TPR). After food ingestion the CO increased from 3.6 ± 0,26 to 4.5 ± 0,33 liters/min (p <0.05) at 45 minutes, and the TPR decreased from 2799 ± 200 to 2177 ± 179 dynes.sec-2 (p<0.05) at 15 minutes. The systolic blood pressure (SBP) decreased from 163 ± 2.2 to 156 ± 2.6 mmHg at 60 min (p<0.05) and the diastolic blood pressure (DBP) from 89 ± 2.0 to 82 ± 2.4 mmHg, p<0.05. After the intake of water, there were no significant alterations in CO or SV, but we observed that TRP increased from 2847 ± 239 to 3229 ± 298 dynes.sec-2, at 45 minutes, p<0.05; and that DBP elevated from 90 ± 3.3 to 95 ± 3.9 mmHg, p>0.05, NS. The SBP increased from 164 ± 2.7 to 175 ± 3.6 mmHg, p<0.05; at 45 minutes. As a result, we conclude that the oral ingestion of water can induce an elevation of blood pressure levels and that effect is secondary to increases in total peripheral resistance. The reduced blood pressure after food ingestion was secondary to the decreases in TPR. These effects could be due to gastropressor reflexes and/or digestive processes.

Key Words
Blood pressure, cardiac output, food ingestion, water ingestion, cardiac systolic function.

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