Variations in cotinine levels in smokers during and after pregnancy.

OBJECTIVE: To compare the antenatal and postnatal cotinine levels in smoking women after controlling for the differences in smoking practices. STUDY DESIGN: A paired comparison of two measurements of cotinine concentration was conducted in 40 smoking women voluntarily recruited in a prenatal education program held in La Fe Hospital, Valencia, Spain, during 1990 and 1991. Cotinine concentration was assayed by gas chromatography in samples of saliva obtained during and after pregnancy. The Wilcoxon matched-pairs test and multiple linear regression analysis were used. RESULTS: The cotinine per cigarette ratio during pregnancy (median 3.53 ng/ml per cigarette) was significantly lower than the ratio in the postnatal testing (median 9.87 ng/ml per cigarette). This difference persisted after allowing for differences in reported cigarette consumption. CONCLUSION: These findings suggest that the available equivalencies between cotinine level and nicotine intake obtained from adult nonpregnant populations cannot be directly applied during pregnancy.

Assessment of exposure to environmental tobacco smoke in nonsmoking pregnant women in different environments of daily living.

The relation between duration of recent exposure to environmental tobacco smoke and salivary cotinine concentration was assessed in a cross-sectional study conducted during the third trimester of pregnancy of 710 nonsmoking women attending a prenatal clinic in La Fe Hospital, Valencia, Spain, between September 1, 1989, and September 30, 1991. A structured interview questionnaire was used to obtain information on duration of exposure to environmental tobacco smoke in the last 3 days to four sources: 1) partner's smoking at home, 2) others' smoking at home, 3) others' smoking at work, and 4) others' smoking in vehicles and in indoor public places. Cotinine levels were determined in saliva samples obtained during interviews. The duration of exposure to any source was positively related to cotinine levels independent of exposure to the other sources (p < 0.05). Self-reporting of the duration of recent exposure was a proxy measure of the integrated dose as assessed by saliva cotinine concentrations. The results underline the need to consider sources of exposure other than partner's tobacco smoke and to assess them individually rather than as an unweighted summative measure.

Exposure to environmental tobacco smoke in nonsmoking pregnant women in relation to birth weight.

The objective of this study was to determine whether birth weight is related to maternal exposure to environmental tobacco smoke. A cohort study was conducted in a sample of 710 nonsmoking women attending a prenatal education program in the third trimester of pregnancy in La Fe Hospital, Valencia, Spain. The duration of exposure to environmental tobacco smoke in the home, at work, and in vehicles and public places was collected by structured questionnaire. Cotinine levels were determined in saliva samples. Multiple regression was used to control for infant's sex and gestational age and for maternal age, height, prepregnancy weight, parity, education, social class, and episodic illnesses during pregnancy. The mean birth weight of infants of women with cotinine levels > 1.7 ng/ml was 87.3 g lower than that of infants of women with cotinine levels in the range 0-0.5 ng/ml (p = 0.048). Birth weight was negatively associated with average weekly duration of exposure in public places (p < 0.05), whereas mothers exposed to the partner's smoke for up to 14 hours/week had infants 177.2 g heavier than those of unexposed mothers. Although the evidence is weak for an effect of exposure to environmental tobacco smoke on the fetus of nonsmoking pregnant women, it may be sufficient to recommend restriction of smoking in enclosed work-and public places to reduce any risk of growth retardation.

Childhood respiratory illness and the home environment. I. Relations between nitrogen dioxide, temperature and relative humidity.

The relation between the use of gas for cooking, nitrogen dioxide (NO2), temperature and relative humidity was investigated in an urban area of northern England. In a pilot study conducted in a random sample of 40 homes measurements of temperature and relative humidity were not significantly different between homes with a gas cooker and homes with an electric cooker but weekly average levels of NO2 were higher in bedrooms (p less than 0.005) and living rooms (P less than 0.01) of gas homes. In the main study conducted in gas cooking homes only, access was gained to 183 (54.3%) of 337 randomly selected homes. No correlation was found in children's bedrooms between with weekly average level of NO2 (range 4.7 to 160.8 ppb) and weekly average temperature (ranged 7.7 to 22.0 degree C; r = 0.05, p greater than 0.10) or relative humidity (range 37.0 to 98.1%; r = 0.07, p greater than 0.10). Levels of NO2 in the bedroom were positively correlated with those in the living room (range 9.0 to 292.2 ppb; r = 0.39, p less than 0.01). Factors which tended to be associated with high levels of NO2 in the home included gas fires, paraffin heaters and use of the cooker for heating and drying clothes.

Childhood respiratory illness and the home environment. II. Association between respiratory illness and nitrogen dioxide, temperature and relative humidity.

The relation of respiratory illness to nitrogen dioxide (NO2), temperature and relative humidity in homes with a gas cooker was investigated in five and six year old children living in an urban area of the northern England. NO2 was measured for one week in the child's bedroom and living room of each home, and temperature and relative humidity were measured in the bedroom only. Information on respiratory conditions experienced by the child and characteristics of the home was collected in a self-administered questionnaire completed by the child's mother. Access was gained to 183 homes (54.3% of 337) where only gas was used for cooking. Complete information was obtained for 179 (93.7%) of 191 children who lived in the 183 homes. After allowing for the effects of age, sex, social class, and number of cigarette smokers in the home and temperature or relative humidity, no statistically significant relation was found between the prevalence of having one or more respiratory conditions and weekly average levels of NO2 in the bedroom (range 4.7 to 160.8 ppb) or living room (range 9.0 to 292.2 ppb). However, the prevalence of having one or more respiratory conditions tended to be highest in homes with high levels of NO2 and lowest in homes with low levels, consistent with earlier findings. A significant positive association was found between the prevalence of respiratory conditions and relative humidity (p less than .05). A harmful effect on health from NO2 cannot be totally dismissed but if it exists it is weak and difficult to detect in small samples of children.

The epidemiology of indoor nitrogen dioxide in the U.K.

The results of three studies on the effect of gas cooking on the lung function of children are reported. The studies which have been carried out in England and Scotland with children aged 6-11, 6-7 and 5-6 years, respectively, show that there is only a weak association between indoor levels of NO2 and respiratory illness. Nevertheless, the consistency of the difference in the rate of respiratory diseases in children from homes with electric and gas cookers suggest there is some hazard to the use of unflued gas appliances which may warrant further epidemiological investigation.

The prevalence of diabetes in a rural population of Jamaican adults.

PIP: The prevalence of diabetes, the interrelationship of blood glucose, serum insulin, and lipids, and their relationship to ischemic heart dise ase in a rural Jamaican community were investigated. The people were mo stly of West African descent. Occupations were primarily agricultural w ith much physical labor. Approximately 80% of total claories in their d iet were from carbohydrates. Of 696 25-64 year old persons, a response rate of 77.3% was achieved. The patients, after an overnight fast, drank a 7-oz bottle of Glucola which was the equivalent of a 100 gm glucose load. Electrocardiograms (EKGs), blood pressure readings, a chest X-ray, and skinfold tests for obesity were done. A family history was obtained. Blood and urine specimens were taken before the glucose was given. 1 hour after the glucose was given, blood and urine specimens were also taken. Those with blood glucose of 180 mg% or more were given a 3-hour glucose tolerance test. Of the 525 persons who had the 1-hour test, 23 were found to be glycosuric. Of these, 11 were not shown to be diabetic by the 3-hour glucose test. Of the 502 with negative urines, 34 were positive on blood tests. The rates increased with age, except in the oldest age groups (p less than .05 for males and p less than .001 for females). There was no relationship between the number of live births and the 1-hour blood glucose tests. There was neither increase in the diagnosis of diabetes nor increase in variance with number of children. The known diabetics were fatter and had higher triglycerides than others. Cholesterol was higher in all male diabetics but not in females. Only 2 persons experiencing effort pain had EKG changes. Data from this study indicate that no statistically significant association exists between levels of glycemia and blood pressure or prevalence of cardiovascular disease. The physical fitness acquired from walking and working in a hilly area may be a factor.^ieng