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Biomedical subjects

J Palmgren

Publications and source records attributed to J Palmgren.

29 records · Page 2Linked to original sources

Exercise, smoking, and calcium intake during adolescence and early adulthood as determinants of peak bone mass. Cardiovascular Risk in Young Finns Study Group.

OBJECTIVE: To evaluate the contribution to peak bone mass of exercise, smoking, and calcium intake in adolescents and young adults. DESIGN: Prospective cohort study with end point measurement (bone mineral density) after 11 years' follow up for lifestyle. SETTING: Five university hospital clinics. SUBJECTS: 264 (153 females, 111 males) subjects aged 9 to 18 years at the beginning of the follow up and 20 to 29 years at the time of measurement of bone mineral density. MAIN OUTCOME MEASURE: Bone mineral density of lumbar spine and femoral neck by dual energy x ray absorptiometry; measures of physical activity and smoking and estimates of calcium intake repeated three times during follow up. RESULTS: In the groups with the lowest and highest levels of exercise the femoral bone mineral densities (adjusted for age and weight) were 0.918 and 0.988 g/cm2 for women (P = 0.015, analysis of covariance) and 0.943 and 1.042 g/cm2 for men (P = 0.005), respectively; at the lumbar spine the respective values were 1.045 and 1.131 (P = 0.005) for men. In men the femoral bone mineral densities (adjusted for age, weight, and exercise) were 1.022 and 0.923 g/cm2 for the groups with the lowest and highest values of smoking index (P = 0.054, analysis of covariance). In women the adjusted femoral bone mineral density increased by 4.7% together with increasing calcium intake (P = 0.089, analysis of covariance). In multiple regression analysis on bone mineral density of the femoral neck, weight, exercise, age, and smoking were independent predictors for men; with weight, exercise, and age for women. These predictors together explained 38% of the variance in bone mineral density in women and 46% in men. At the lumbar spine, weight, smoking, and exercise were predictors for men; and only weight for women. CONCLUSIONS: Regular exercise and not smoking is important in achieving maximal peak bone mass in adolescents and young adults.

Absorptiometry, Photon↗

Virulence-associated characteristics of Escherichia coli in urinary tract infection: a statistical analysis with special attention to type 1C fimbriation.

The relative virulence (defined as odds ratio) associated with different O and K antigens, adhesins and hemolysin production of Escherichia coli strains was assessed by separate and multivariate logistic regression analyses comparing 383 strains isolated from urine of adults with a urinary tract infection with 287 fecal strains from healthy adults; special interest was paid to evaluating the role of type 1C fimbriation. Type 1C fimbriae, found on 14% of UTI and 7% of fecal strains, were associated with O groups O2, O6, O18, and O75, with capsular type K5, with mannose-resistant (both P and non-P) adhesins, and with hemolysin production. In separate analyses, O8 (odds ratio 5.9) and O75 (9.2), capsular types other than K1 (1.9-2.1), P (2.9) and non-P mannose-resistant (17.4) adhesins, and hemolysin production (3.1) were each associated with high relative virulence compared to O1, Rough, and K1 phenotypes or lack of mannose-resistant adhesins or hemolysin. All these virulence effects were independent of type 1C fimbriation. In multivariate analysis, joint variation between factors decreased the apparent virulence-promoting effect of type 1C fimbriae, O6 antigen and hemolysin but increased that of other adhesins. Especially high relative virulence (odds ratio 404.2) was associated with the combination of O75:K5:non-P mannose-resistant adhesin identified on seven UTI but no fecal strains.

Adult↗

Lifetime menstrual activity--indicator of breast cancer risk.

A case-control study of 67 cases of breast cancer and 157 controls was conducted to investigate the role of different behavioral, reproductive, and hormonal factors and to develop a unifying indicator of breast cancer risk. The results confirm previous reports of the influence of smoking on the risk of breast cancer. Age at menarche was found to be a risk factor among the premenopausal women. Late age at menopause was suggestive of an increase in risk. Long use of oral contraceptive or estrogen supplementation were risk-enhancing both pre- and postmenopausally. Lifetime duration of menstrual activity (LMA) combines age at menarche and menopause, parity, and lactation into a biologically plausible model. Our findings concerning LMA support its role as a determinant of breast cancer.

Adult↗

Controlling for total energy intake in regression models for assessing macronutrient effects on disease.

This paper illustrates the relationships between the (i) the standard multivariate method, (ii) the energy-adjusted method and (iii) the energy decomposition method for controlling for total energy intake. The setting is a general regression model which includes linear, logistic and Cox regressions. The discussion is confined to effects of macronutrients and to situations in which total energy intake is associated with disease. Pike, Bernstein & Peters [(1989) Am. J. Epidemiol. 129, 1312-1313] show how the three methods relate to each other and that the choice between them is a matter of taste. Here the relationships are illustrated using Venn-type diagrams. However, the rationale for all current controlling procedures relies on the assumption of external factors acting uniformly over different sources of energy. This assumption should be challenged. Furthermore, if individual macronutrients have independent, possibly even opposite effects on the risk for disease, then adjustment of any one of them will be relative to the effect of the others. This might not be satisfactory. Current methodology does not resolve these problems, and more elaborate data as well as further thought is needed.

Energy Intake↗

Serum beta-carotene before and after beta-carotene supplementation.

A two-month double-blind, placebo-controlled supplementation study of oral beta-carotene (20 mg daily) was conducted. Two hundred and twenty two 30-69 year old men were randomized into either a beta-carotene or placebo group, and serum samples were obtained at baseline, follow-up (2 months), and up to 12 weeks post-supplementation. Serum beta-carotene increased on average 10-fold in the beta-carotene group, from 0.53 +/- 0.32 mumol/l (mean +/- SD) at baseline to 4.99 +/- 2.47 mumol/l at follow-up (P less than 0.0001), and beta-carotene levels remained elevated up to 12 weeks post-supplementation (0.61 +/- 0.15 mumol/l). No changes in serum retinol, alpha-tocopherol, or total cholesterol were observed. At baseline, serum beta-carotene levels were positively correlated with dietary beta-carotene (r = 0.29) and inversely correlated with body mass index and serum gamma-glutamyltransferase (r = -0.33 and r = -0.40, respectively). The inverse association with body mass index and serum gamma-glutamyltransferase persisted during active supplementation, whereas the positive association with dietary beta-carotene disappeared. In multivariate analysis, serum cholesterol was also positively associated with serum beta-carotene levels both before and after supplementation. Baseline serum beta-carotene was the factor most strongly associated (positively) with serum beta-carotene after supplementation. Our study highlights the importance of several factors which affect serum beta-carotene.

Administration, Oral↗

Variability in nutrient and food intakes among older middle-aged men. Implications for design of epidemiologic and validation studies using food recording.

The authors conducted a dietary methodology study in 1984 in Finnish men aged 55-69 years in order to validate two dietary assessment instruments being used in the US-Finland Alpha-Tocopherol, Beta-Carotene Lung Cancer Prevention Trial. Twelve 2-day food records collected from 162 men over a 6-month period, including every day of the week, served as the reference measure. This report focuses on three important questions for investigating diet and disease relations: 1) How many days are necessary to classify "usual" intake? 2) Is there loss as a result of using consecutive days? 3) Which days are necessary for assessment and classification of "usual" diet? A repeated-measures regression model was used to estimate the variance components and the effects of consecutive days, weekday (weekday vs. weekend), and season. Correlations between the averages of different numbers of days of food records and "true" usual intake were examined along with the resulting attenuations in relative risk. Results suggest that 7-14 days are required to adequately classify most individuals into categories of intake for most nutrients and some foods. There appears to be some loss of information from using consecutive days rather than days further apart. Weekday/weekend differences in mean intakes are slight, and the rank ordering of individuals appears to be preserved. A moderate seasonal effect is shown for classification of fruits, but only a slight one is seen for micronutrients and berries. Implications for the design of epidemiologic and validation studies are discussed.

Aged↗

Risk factors of invasive Haemophilus influenzae type b disease among children in Finland.

A population-based matched case-control analysis of risk factors of invasive Haemophilus influenzae type b (Hib) disease was conducted in Finland in 1985 and 1986 before large-scale Hib vaccinations; 117 consecutive child patients with invasive Hib disease and 225 control subjects matched for age, sex, and residence were studied. In the multivariate analysis, day care outside the home was found to increase the risk of invasive Hib disease (odds ratio 5, 95% confidence interval 2.3 to 11), with the highest risk among children less than 2 years of age; this risk was significantly higher within the first month of attendance than later on (p = 0.02). The existence of siblings less than 7 years of age was found to be a risk factor, especially for the younger children (odds ratio 8.6, 95% confidence interval 2.6 to 52 for children less than 1 year of age), and the odds ratio increased approximately twofold with each additional sibling. A history of otitis media and previous hospitalizations were further risk factors for invasive Hib disease (odds ratio 2.2, 95% confidence interval 1.2 to 3.9, and odds ratio 1.9, 95% confidence interval 1.0 to 3.4, respectively). Breast-feeding for longer than 6 months was found to be protective (odds ratio 0.47, 95% confidence interval 0.3 to 0.9). The amount of Hib disease in different populations will vary with the incidence of these risk factors.

Age Factors↗

Reproducibility and validity of dietary assessment instruments. I. A self-administered food use questionnaire with a portion size picture booklet.

A self-administered food use questionnaire which included 276 food items and mixed dishes and a portion size picture booklet with 122 photographs was developed for a large lung cancer intervention trial among approximately 27,000 Finnish men aged 50-69 years. The reproducibility and validity of this questionnaire were studied from March to October 1984. In the reproducibility study, 121 men aged 55-69 years completed the questionnaire three times, at three-month intervals. The intraclass correlations varied from 0.56 for vitamin A to 0.88 for alcohol, with most falling between 0.60 and 0.70. In the validity study, 190 men of similar age kept food consumption records for 12 two-day periods, distributed evenly over a period of six months, and filled in the questionnaire both before and after this period. Correlations between nutrient intake values from the food records and the food use questionnaires ranged from 0.40 for selenium to 0.80 for alcohol. Among subjects who belonged to the lowest quintile on the basis of the food record measurement, an average of 51 per cent fell into the same quintile and 76 per cent fell into the lowest two quintiles when they were categorized on the basis of the food use questionnaire. Findings were similar for the upper tail of the distribution. These data indicate that the self-administered food use questionnaire is useful for measuring individual or group intakes for a variety of nutrients.

Aged↗

Reproducibility and validity of dietary assessment instruments. II. A qualitative food frequency questionnaire.

The reproducibility and validity of a food frequency questionnaire designed to measure intakes of total fat, saturated and polyunsaturated fats, vitamins A, C, and E, selenium, and dietary fiber were tested from March to October 1984 among 297 Finnish men aged 55-69 years. The questionnaire asked about consumption of 44 food items. In the reproducibility study, 107 subjects filled in the questionnaire three times, at three-month intervals. Intraclass correlations varied from 0.52 for vitamin A to 0.85 for polyunsaturated fat. In the validity study, 190 subjects kept food consumption records for 12 two-day periods distributed evenly over a period of six months and filled in the questionnaire both before and after this period. Correlations between the nutrient intake values from the food records and those from the food frequency questionnaires ranged from 0.33 for selenium to 0.68 for polyunsaturated fat. On the average, 40-45% of the subjects in the lowest and highest quintiles based on food records were in the same respective quintiles when assessed by the food frequency questionnaire, and 70-75% were in the two lowest and two highest questionnaire quintiles, respectively. The food frequency questionnaire and a quantitative food use questionnaire tested in the same study were compared. Use of these two instruments in large-scale epidemiologic studies is discussed.

Ascorbic Acid↗

Haemophilus influenzae type b strains of outer membrane subtypes 1 and 1c cause different types of invasive disease.

Of 275 consecutive Haemophilus influenzae type b (Hib) strains isolated from children with invasive disease in Finland in 1985-86, 74% were of the common European outer membrane protein (OMP) subtype 1 and 22% were of OMP subtype 1c, which is usually rare. Strains of subtype 1c caused proportionately more meningitis and less epiglottis than did strains of subtype 1c. Furthermore, children with disease due to strains of subtype 1c were younger than those with disease due to strains of subtype 1. The significant difference in association between subtype and the diagnosis of epiglottitis or meningitis remained even when the strong influence of age was accounted for. This finding may suggest a true difference in the virulence between these subtypes not previously demonstrated for Haemophilus influenzae type b.

Age Factors↗