Biomedical subjects

S V Jaque-Fortunato

Publications and source records attributed to S V Jaque-Fortunato.

3 recordsLinked to original sources

PubMed1996

A comparison of cross-sectional and longitudinal methods of assessing the influence of pregnancy on cardiac function during exercise.

To evaluate the influence of pregnancy on resting and exercise cardiac function, we studied 16 nonpregnant and 26 pregnant females in a two-phase study. During phase I, all pregnant subjects (P1) (mean gestational age = 29.5 +/- 7 weeks) were compared with 16 control (C) subjects. In phase II, 8 of the pregnant subjects (P2) (mean gestational age = 32.6 +/- 6 weeks) were evaluated again at 12.5 +/- 7 weeks postpartum (PP). Using Collier's CO2 rebreathing technique, exercise cardiac output (Q) was measured on a cycle ergometer during rest and at three submaximal work levels (25, 50, and 75 W), during the last minute of 5 to 7 minutes of steady-level power output. Metabolic parameters [ventilation (VE), heart rate (HR) and oxygen consumption (VO2)] were measured during the submaximal tests and throughout the progressive increase in work after the last measure of Q, until peak VO2 was achieved. The results from the phase I comparison indicated (as expected) higher resting heart rates [(90.0 +/- 3 P1; 81.8 +/- 3 bpm C), ventilation (9.5 +/- 0.3 P1; 7.5 +/- 0.5 L min-1 C), and resting oxygen consumption (0.263 +/- 0.07 P; 0.221 +/- 0.01 L min-1 C) associated with pregnancy, and these findings were similar when the pregnant subjects were compared with their postpartum values. Analysis of the various indices of cardiac function [Q, stroke volume (SV), and arteriovenous oxygen difference (A-VO2 diff)] resulted in statistically higher resting Q in pregnancy when compared with C and PP conditions. No resting differences were observed for SV or A-VO2 diff in either phase of the study. The results of the submaximal exercise tests indicated no significant differences in HR nor VO2 between P1 and C; however, P2 had significantly higher submaximal heart rates and oxygen consumption when compared with PP. Further, no significant differences were observed between P1 and C for Q, SV or A-VO2 diff, whereas P2 versus PP resulted in significantly lower SV and higher A-VO2 diff in the pregnant subjects. These findings suggest that pregnancy/control versus pregnancy/ postpartum studies yield statistically different results and that an effort needs to made by the research community to develop standardized methodologies to evaluate physiological processes in pregnancy.

Arteries↗

PubMed1996

A comparison of the ventilatory responses to exercise in pregnant, postpartum, and nonpregnant women.

To evaluate the influence of pregnancy on resting and exercise pulmonary function, we studied 16 nonpregnant and 26 pregnant females in a two-phase study. During phase I, all pregnant subjects (P1) (mean gestational age = 29.5 +/- 7 weeks [X +/- SD]) were compared with 16 control (C) subjects. In phase II, 8 of the pregnant subjects (P2) (mean gestational age = 32.6 +/- 6 weeks) were evaluated again at 12.5 +/- 7 weeks' postpartum (PP). Exercise respiratory function was measured during work on a cycle ergometer during rest and at three submaximal work levels (25, 50, and 75 W), during the last minute of 5 to 7 minutes of steady-level power output. Ventilatory parameters [ventilation (VE), ventilatory frequency (VF), tidal volume (TV), ventilatory equivalent for oxygen (VE/VO2) and ventilatory equivalent for carbon dioxide (VE/VCO2)] and metabolic parameters [oxygen consumption (VO2), oxygen pulse, carbon dioxide production (VCO2), respiratory exchange ratio (RER), and plasma lactate (HLA)] were measured during the submaximal tests and throughout the progressive increase in work after the 75 W work load, until peak VO2 was achieved. The results from the phase I comparison indicated (as expected) higher resting ventilation, tidal volume, oxygen consumption, carbon dioxide production, and respiratory exchange ratio associated with pregnancy, and these findings were similar when the pregnant subjects were compared with their postpartum values. Plasma lactate levels, although similar in the phase I comparison, were significantly higher during pregnancy when compared with postpartum values. No resting differences were observed for VF, O2 pulse, VE/VO, or VE/VCO2 in either phase of the study. The results of the submaximal exercise tests indicated higher submaximal levels of VE, VF, VE/VO2, VE/VCO2 in P1 versus C; however, P2 had significantly higher VE, TV, VO2, VE/VCO2, when compared with PP. The influence of pregnancy on VCO2 and RER differed by workload in both sets of comparisons. Furthermore, no significant differences were observed between P1 and C and P2 and PP for plasma lactate levels. These findings suggest that pregnancy/control versus pregnancy/postpartum studies yield different results in both ventilatory and metabolic comparisons. Consideration must be given to the type of study when discussing and applying the findings.

Adult↗

PubMed1996

Body composition in pregnancy.

Concern over the influence of pregnancy-related alterations in hydration has prompted questions regarding the accuracy of using standard methods of determining body composition. We sought to investigate whether differences exist between body composition determined at 30 weeks and 39 weeks of gestation and postpartum, when measured by both bioelectrical impedance and hydrostatic weighing. This preliminary assessment of nine subjects suggests that the method used to calculate body composition during pregnancy can alter the influence of gestational age on body composition. The mechanisms underlying the differing results bear further investigation, as does the search for an accurate and reliable method for assessing body composition during pregnancy. Further research addressing these mechanisms is crucial to determining the relationship between changes in maternal fat and both maternal and fetal well-being.

Body Composition↗