Atsuhiko Fukuoka

Effect of Serum Leptin Levels on Hypercapnic Ventilatory Response in Obstructive Sleep Apnea

Background: Leptin levels have been reported to be higher in patients with obstructive sleep apnea (OSA) than in control subjects with matching age and body mass index (BMI). Although animal studies have shown that leptin augments hypercapnic ventilatory response (HCVR), the effect of leptin on HCVR has not been clarified in OSA. Objectives: To investigate whether leptin could augment HCVR during wakefulness in patients with OSA. Methods: Of 134 consecutive patients with OSA, 13 eucapnic and 16 hypercapnic patients with OSA, and 12 control subjects matched for sex, age, and BMI were selected. Fasting serum leptin levels were collected, and HCVR during wakefulness assessed by the slope between minute ventilation and end-tidal PCO2. Results: There was a significant positive relationship between serum leptin levels and HCVR in the group including control subjects and eucapnic patients with OSA (r = 0.42, p < 0.05). Subgroup analyses suggest that serum leptin levels and HCVR were significantly higher in eucapnic patients with OSA than in control subjects. On the other hand, hypercapnic patients had lower HCVR than eucapnic patients (p < 0.05), whereas serum leptin levels were similar between the two OSA subgroups. Conclusion: Leptin levels and HCVR are correlated as long as the eucapnic condition is maintained. We speculate that a stimulating effect of leptin on HCVR may be masked by the hypoventilation state.

The relation of fat-free mass to maximum exercise performance in patients with chronic obstructive pulmonary disease.

To assess the factors determining maximum exercise performance in patients with chronic obstructive pulmonary disease (COPD), we examined nutritional status with special reference to body composition and pulmonary function in 50 stable COPD patients. Nutritional status was evaluated by body weight and body composition, including fat mass (FM) and fat-free mass (FFM) assessed by bioelectrical impedance analysis (BIA). Exercise performance was evaluated by maximum oxygen uptake (Vo2max) on a cycle ergometer. A total of 50 patients (FEV1= 0.98 L) was divided randomly into either a study group (group A, n= 25) or validation group (group B, n= 25). Stepwise regression analysis was performed in group A to determine the best predictors of Vo2max from measurements of pulmonary function and nutritional status. Stepwise regression analysis revealed that Vo2max was predicted best by the following equation in group A: Vo2max (mL/min) = 10.223 × FFM (kg) + 4.188 × MVV (L/min) + 9.952 × DLco (mL/min/mmHg) − 127.9 (r= 0.84, p < 0.001). This equation was then cross-validated in group B: Measured Vo2max (mL/min) = 1.554 × Predicted Vo2max (mL/min) − 324.0 (r= 0.87, p < 0.001). We conclude that FFM is an important factor in determining maximum exercise performance, along with pulmonary function parameters, in patients with COPD.

Nocturnal hypoxic stress activates invasive ability of monocytes in patients with obstructive sleep apnoea syndrome

Background and objective:  Obstructive sleep apnoea syndrome (OSAS) is known to be a risk factor for cardiovascular events. However, the precise mechanism has not been fully elucidated. OSAS‐induced hypoxic stress may promote the production of inflammatory cytokines and chemokines by monocytes, which has a crucial role in the development of atherosclerosis. In addition, adhesion to the vascular endothelium and transendothelial migration of monocytes are considered to induce atherosclerosis. The aim of this study was to investigate the effects of hypoxic stress on the invasive ability of monocytes in OSAS.

The Change in Body Composition After Bilateral Lung Volume Reduction Surgery for Underweight Patients with Severe Emphysema

Abstract. The aim of this study was to examine the short-term effect of lung volume reduction surgery (LVRS) on body composition and other nutritional indicators in 28 patients with emphysema underwent thoracoscopic LVRS. Functional tests, body weight (BW), and body composition were measured before and 6 months after surgery. Mean daily caloric intake (CI) was estimated by 3-day dietary record as well. Fat-free mass (FFM) and fat mass (FM) were assessed by bioelectrical impedance analysis (BIA). FEV1.0 and Vo2max have improved after LVRS by 35.2% and 23.8%, respectively. Preoperatively, 75% of patients were underweight (% ideal body weight (%IBW) <90) with the mean %IBW at 84.5%. BW, CI, and FFM increased significantly after LVRS, whereas FM was unchanged. The change in BW correlated significantly with the change in FEV1.0, MVV, and Vo2max (p < 0.01) but not with CI. Bilateral LVRS results in an increase in FFM and functional improvement for underweight patients with severe emphysema, and it may contribute to the improvement in maximal exercise capacity.

Tuberculous peritonitis developing during chemotherapy for pulmonary and intestinal tuberculosis: A case report

Abstract:  This report is of a case of tuberculous peritonitis that developed during antituberculous chemotherapy. A 54‐year‐old man had been diagnosed as all‐drug susceptible pulmonary and intestinal tuberculosis, and treatment with isoniazid, ethambutol and rifampicin had been initiated. About 5 months later, while still undergoing therapy, a large amount of ascites developed. A diagnostic laparoscopy was performed but due to the adhesion between the greater omentum and the parietal peritoneum, intestinal perforation occurred. An emergency operation was performed and the diagnosis of tuberculous peritonitis was confirmed. There are few reports of abdominal tuberculosis developing during antituberculous chemotherapy. In this case a paradoxical response may have been involved in the pathogenesis.

Distribution of Bone Mineral Content Is Associated with Body Weight and Exercise Capacity in Patients with Chronic Obstructive Pulmonary Disease

Background: Although low bone mineral density is highly prevalent in patients with chronic obstructive pulmonary disease (COPD), the distribution of the reduced bone mass has not been fully elucidated. Objectives: To determine regional bone mass loss in patients with COPD and investigate whether the change in distribution may be associated with body weight loss and functional capacity. Methods: Body mass index (BMI) was assessed, and height squared indices were derived for the bone mineral content index (BMCI) of the arms, legs and trunk by dual-energy X-ray absorptiometry in 45 male patients with COPD and 12 age- and sex-matched control subjects. Pulmonary function tests were performed, and maximal oxygen uptake (V·O2max) was measured. Results: The BMCI was lower in the total bone, legs and trunk of patients with COPD than in control subjects, although the BMCI in the arms was similar between the groups. BMI correlated significantly with the BMCI in all 3 segments. Bone mineral content (BMC) in the trunk, expressed as a percentage of total BMC (BMC trunk/total BMC), correlated significantly with BMI. The BMCI in the trunk was closely related with V·O2max but not with airflow limitation. Conclusions: There was a regional difference in BMC reduction, but a predominant reduction of bone mass in the trunk was not associated with the severity of airflow limitation but rather with body weight loss and exercise intolerance. These data suggest that body weight loss and exercise intolerance are important risk factors for vertebral fracture in patients with COPD.