ABSTRACT
There is a paucity of experimental data on the actual mechanism of insulin-induced changes on the myocardial function. In the present study we investigated the myocardial contractile, response to an oral glucose load using echocardiography. Fifteen healthy volunteers were studied after overnight fast and 150 minutes after the oral load of 75 g glucose. Oral glucose load caused an increase in plasma glucose and insulin levels, which was accompained by a significant increase in left ventricular shortening (from 35.2 + 0.7 per cent at baseline, to 38.5 + 0.6 per cent and 39 + 0.9 per cent at 30 and 60 minutes post glucose load, respectively [P<0.05 vs baseline]; ejection faction rose from 0.73 per cent + 0.01 to 0.77 per cent + 0.01 (P<0.05); pressure rate product increased from 7.29 + 0.2 to 8.31 + 0.3 mmHg x beats per min (P<0.007) and heart rate enhanced from 68.3 + 1.9 to 74 + 1.6 (P<0.034) and 75.3 + 1.5 beats per min (P<0.008) at 60 and 90 minutes after glucose, respectively. Meanwhile, mean arterial presure decreased significantly (10+1.5 per cent, P<0.018) when compared to basal values. These results indicate a significant change in the myocardial contractile response to an oral glucose load, probably related to baroreceptor reflex response as well as an overridden by a potent vasodilatador action of insulin. Nevertheless, we could not rule out the cardiac effects may also be due an insulin-induced sympathetic activation or a direct myocardial effect.
Subject(s)
Adult , Female , Humans , Blood Glucose/metabolism , Echocardiography , Glucose/administration & dosage , Insulin/blood , Myocardial Contraction/drug effects , Administration, Oral , Blood Pressure/drug effects , Glucose Oxidase/analysis , Glucose Tolerance Test , Heart Rate/drug effects , Insulin/metabolism , Radioimmunoassay , Regression Analysis , Ventricular Function, Left/drug effectsABSTRACT
The frequency of glucose intolerance was studied in 106 patients with pulmonary tuberculosis attending Nazimabad Chest Clinic. Diagnosis was based on X-ray and a positive sputum smear. An oral glucose tolerance test [OGTT] was performed and evaluated according to the WHO criteria. Glucose intolerance was detected in 52 [49%] patients, 31 Impaired Glucose Tolerance [IGT], 21 Diabetes Mellitus [DM]. After adequate antitubercular therapy and sputum conversion, the OGTT was repeated in 23 cases. Of these 13 [56.5%] patients had a normal glucose tolerance indicating that glucose intolerance observed during active pulmonary tuberculosis improves or normalizes after adequate therapy