Intramyocellular lipid variations in active older men: relationship with aerobic fitness.

AIMS: Intramyocellular lipid (IMCL) variations in older men are poorly explored. In young adults, IMCL can be influenced by both diet and exercise interventions; this flexibility is related to aerobic fitness. We evaluated in active older adults the influence of maximal aerobic capacity on short-term diet and exercise-induced variations in IMCL stores. METHODS: Intramyocellular lipids were measured by (1) H magnetic resonance spectroscopy ((1) H-MRS) after a 3-day fat depletion-replenishment diet (IMCL(FDR) ) and immediately after a 2-h exercise at 50% VO(2) max (IMCL(FDR) (_) (EX) ). To further explore diet influence, the protocol was repeated after a high-fat diet (HF), with both pre- and post-exercise measurements (IMCL(HF) and IMCL(HF) (_) (EX) ). RESULTS: In active older men (69.8 ± 5.2 years), IMCL(FDR) was lowered by exercise (IMCL(FDR) = 3.45 ± 1.52 vs. IMCL(FDR) (_) (EX) = 2.74 ± 1.15 mmol kg(-1) wet weight, P < 0.05), and exercise-induced variations were correlated to the initial store (P < 0.05, r = -0.72). IMCL(FDR) was linked with aerobic fitness (P < 0.05, r = 0.76), when adjusted by fat mass. IMCL(HF) was lower than IMCL(FDR) (P < 0.05), decreased after exercise (P < 0.05) and varied also as a function of initial store (P < 0.05, r = -0.89), but without link with aerobic fitness. Finally, diet-induced IMCL store variations were positively linked to aerobic fitness (P < 0.05, r = 0.89). CONCLUSION: Variations of the IMCL stores in physically active older adults appear related to aerobic fitness, with similarly fast adaptation to short-term interventions combining diet and exercise as young active adults.

[Value of the positive exercise test without angina (after myocardial infarct)]. / Valeur de l'épreuve d'effort positive sans angor (après infarctus du myocarde).

In order to determine the value of a positive exercise test (ET) (i.e. ischaemic ST depression) without chest pain observed after a myocardial infarction (MI), 102 ET's were reviewed. ET was performed without anti-ischaemic drugs. The mean time-lag between MI and ET was 51 +/- 55 months. The MI was inferior in 26 cases, inferior and/or posterior in 74 cases and of undetermined location in 2 cases. Thirty patients had both ST depression and chest pain (group 1); 35 had electrocardiographic signs of ischaemia without pain (group 2), and 37 had neither chest pain nor signs of ischaemia (group 3). Age, sex ratio, site of infarction and time-lag between MI and ET were similar in all three groups. The post-ET follow-up period was 33 +/- 18 months (range: 6 to 66 months); 2 patients in group 3 were lost sight of. There was no significant difference between groups 1 and 2 as regards total duration of ET, workload attained, heart rate, systolic arterial pressure, pressure-rate product and amplitude of ST depression at maximum exercise level. Group 3 differed from the other 2 groups in workload attained (p less than 0.05) and in pressure-rate product (p less than 0.05 vs group 1, p less than 0.01 vs group 2). There was no significant difference between groups 1 and 2 as regards post-ET events (recurrent angina, reinfarction, coronary bypass, transluminal angioplasty).(ABSTRACT TRUNCATED AT 250 WORDS)