Work capacity and cardiopulmonary performance were studied in a group of 11 young obese subjects (BMI 39.9 kg/m²) and a group of 10 young normal subjects (BMI 22 kg/m²). First of all they underwent an incremental cycle ergometer test up to exhaustion. Subsequently, every subject of the two groups performed a constant work rate test at different work loads to estimate cardiac output (q̇) below anaerobic threshold (AT) by a 20-second CO₂ rebreathing method. Obese subjects had a significantly lower AT (79 vs. 109 W). The ratio between oxygen uptake and heart rate (v̇O₂/HR) (O₂ pulse) was higher in the obese group; nevertheless, this variable became significantly lower if we took into consideration the ratio between O₂ pulse and kilogram fat-free body mass or kilogram body weight. Both these observations suggest that their reduced work tolerance is linked with a reduced oxygen supply to the muscles in activity. q̇ increased in similar ways in obese and normal subjects at the preset work rates. The ratio q̇/body surface (cardiac index; CI) that we considered in order to try to minimize the differences in body sizes between the two groups, increased less in response to increasing work rates in our obese subjects than in normal subjects. As a whole, these data appear to be in line with a relatively less efficient cardiac performance during progressive work rates in obese subjects.

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During physical exercise K(+) and catecholamines kinetics differ significantly in obese subjects vs normals and they may justify a less prompt cardiac response at the higher work-loads and a lower work capacity. The present data can be interpreted in the light of the insulin resistance syndrome of obesity, which causes an abnormal regulation of the Na-KATPase and of K(+) channels during physical exercise. The results of the present study may be relevant to nutritionists when suggesting physical exercise to obese subjects.

Aerobic plus anaerobic training seem to produce a greater response in lipid metabolism and not significant modifications in glucose indexes; then, in training prescription for obesity, we might suggest at starting weight loss program aerobic with short bouts of anaerobic training to reduce fat mass and subsequently a prolonged aerobic training alone to ameliorate the metabolic profile.

Objectives: To assess the diagnostic value of bronchoalveolar lavage fluid (BALF) ferritin as a lung tumor marker by comparing serum and BALF ferritin concentrations in patients with peripheral lung cancer versus control subjects with benign lung disease, and to examine the theory of ferritin compartmentalization around the tumor area by comparing ferritin concentrations in serum and bilateral (affected and unaffected side) BALF in cancer patients. Methods: Four groups of patients were investigated: 10 control nonsmokers, 10 control smokers, 10 smokers with chronic obstructive pulmonary disease (COPD), and 22 patients with primary bronchogenic carcinoma. A bronchoalveolar lavage (BAL) was performed in all subjects (both sides in 13 oncological patients, one side in the others) and samples of BALF and blood were submitted to biochemical analysis. Results: As a lung tumor marker, BALF ferritin showed 54% sensitivity and 93% specificity and serum ferritin 22% sensitivity and 93% specificity. A significant difference was observed between the two sides in the cancer patients (p = 0.033), and between BALF ferritin from the affected side and COPD patients (p = 0.025). Greater differences were obtained when BALF ferritin in the affected side of cancer patients was compared with values in both control nonsmokers (p < 0.0001) and control smokers (p < 0.001). Conclusions: These findings seem to confirm the relative diagnostic value of BALF ferritin as a lung tumor marker and the theory of ferritin compartmentalization. However, further studies are required to clarify the relations between iron and ferritin on the one hand and inflammation, tumorigenesis and host response on the other.