Fumio Osaka

Urinary hydroxyproline to creatinine ratio as a biological effect marker for exposure to NO2 and tobacco smoke

In order to study the relationship between NO2 exposure and effects, we monitored personal NO2 exposures and the hydroxyproline to creatinine ratio in urine of about 800 women in two communities near Tokyo. Monitoring was conducted during two seasons, winter and summer 1982. The hydroxyproline to creatinine ratio (HOP:C) was determined from urine samples collected in the early morning. Daily average personal NO2 exposures (ENO2) were measured by using a filter badge. In both seasons, HOP:C was found to have significant correlation with ENO2 and active and passive smoking. In addition, subjects living near major roads had significantly higher HOP:C levels in the summer compared with those living far from them. We hypothesize that these higher HOP:C levels in the summer were due to higher air exchange rates resulting in infiltration of automobile exhaust into homes. ENO2, however, did not correlate with either the distance of the subjects house from major roads or with the amount of smoking. Stepwise multiple regression analysis revealed that HOP:C could be predicted by personal NO2 exposures and smoking variables with a high level of confidence.

Behavior of urinary hydroxyproline and cigarette smoking effect in silicosis.

This study was conducted through regular pneumoconiosis examination according to the law on 1, 096 employees of medium and small-sized ceramic enterprises in Tokai district in 1981-82.Interview examination with BMRC questionnaire, X-ray examination and measurement of urinary hydroxyproline to creatinine ratio (HOP ratio) were carried out in order to elucidate the relationship between silicosis and urinary HOP ratio and to demonstrate the effect of smoking on pneumo-fibrosis. Grade of silicosis was classified into five types (0 to 4) based on the Japanese Classification of Radiographs of Pneumoconioses.In evaluating the behavior of urinary HOP ratio, when smoking factor is added in the early grade of pneumofibrosis (type 1 and type 2), collagen decomposition rate is rapidly repressed and fibroplastic conditions develop to the final grade as type 3 and type 4, although smoking itself does not seem to induce pneumofibrosis.To exclude the effects of smoking, nonsmoking group was used for measurement of HOP ratio by grade. The HOP ratio in type 0 was lowest and HOP ratio increased in the order of type 1 and type 2. The turning point was found in type 2 and their HOP ratio decreased one after another.The turning point shifted from type 2 to type 3 in the case of non-smokers without any index symptoms by BMRC questionnaire and also shifted to type 1, in the case of non-smokers with them. Shifting of turning point suggests that index symptoms also promote fibroplastic activities.