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Biomedical subjects

L Munan

Publications and source records attributed to L Munan.

At least 19 recordsLinked to original sources
PubMed1979

Patterns of change in selected serum chemical parameters of middle and later years.

Six serum constituents known to vary with renal function were analyzed in a probability sample of 500 persons 55 years and over, and their sex trends compared to other ages. Creatinine, BUN and alkaline phosphatase are elevated in this group whereas calcium is low and phosphorus strikingly so, especially in males. A possible explanation lies in age-related renal parenchymal changes which influence both glomerular filtration and tubular functions in ways that differ from true renal disease. These results have directed implications for geriatric diagnosis and therapy.

Age Factors↗
PubMed1978

A comparison of dietary methods in epidemiologic studies.

Three methods of estimating group and individual dietary consumption have been developed and assessed in a case-control study of diet and breast cancer. The methods comprised a 24-hour recall, a detailed quantitative diet history directed to the most recent two-month period and the two-month period six months before, and a four-day diet diary. There is a high degree of correlation between the estimates of food consumption for the controls using each of the methods. The highest estimate was obtained from the diet history, with a slightly higher estimate in the period six months before than the current period, while the lowest is found in the 24-hour recall. The latter corresponds with the same method in a Nutrition Canada Survey. It is concluded that all methods ara applicable to case-control studies, but the diet history is preferred when current food intake may be influenced by a disease.

Breast Neoplasms↗
PubMed1978

A study of diet and breast cancer.

A case-control study has been conducted in four areas in Canada in which 400 cases of breast cancer matched by age and marital status with neighborhood controls were administered a medical and dietary history questionnaire, a 24-hour recall for dietary information and a four-day diet record. The Study has produced evidence of an association between an increased intake of nutrients, especially total fat, in both pre-menopausal and post-menopausal women with breast cancer. Reasons why a weak association might have been anticipated are discussed, and it is concluded that in reality the association is stronger. Furthermore, its consistency with other evidence, both experimental and international, suggests that it is causal.

Age Factors↗
PubMed1978

An epidemiologic study of breast cancer.

A case-control study has been conducted in four areas of Canada in which 400 cases of breast cancer matched by age and marital status with neighborhood controls were administered medical and dietary questionnaires. The study is suggestive of an increased risk of breast cancer in post-menopausal women with younger age at menarche and an increased risk with delay of age at natural menopause. No protective effect of early age at first pregnancy was demonstrated in either pre- or post-menopausal women. An increased frequency of pregnancies of four months duration or less was found in cases compared to controls and a greater frequency in pre-menopausal cases compared to controls of a history of irregular menstrual periods. In pre-menopausal women no association has been found between increased height and weight as risk factors for breast cancer. For post-menopausal women, however, a weak association with increased height has been found, while a strong association with increased weight both at the time of menopause and the 12 months preceding diagnosis has ben confirmed.

Adolescent↗
PubMed1977

Enzymatic activity patterns in probability population samples. Serum lactate dehydrogenase.

Sex- and age-specific serum lactate dehydrogenase values provided by a natural population of 2,378 individuals selected by a multistage area cluster probability sampling scheme are given. The activity of this enzyme has definite sex and age associations over the age range studied (larger than or equal to 10 years). In both sexes, it is characterized by elevations in preadolescents, by a sharp decrease in adolescent groups, and by a gradual increase in adult and senescent groups, which, however, does not bring it back to earlier levels. Males have higher mean serum lactate dehydrogenase activities than females in most age groups until about 50 years of age. Unusually high activities have been found in this study, compared with those found in two other widely separated areas in North America using the same assay procedures.

Adolescent↗
PubMed1977

Haematologic profile of natural populations: red cell parameters.

Age-sex specific reference values and frequency distribution of erythrocyte parameters were derived from a representative sample of a natural population consisting of 1094 men and 1284 women between 10 and 96 years of age. Some differences have been found between previously reported reference values and those presented here, the importance of which lies not so much in their magnitude as in the fact that the latter are based upon a probability sample of a natural population unselected as to disease and are presented as percentile distributions by age and sex rather than as the more frequently used normal distribution. These results are intended for use as reference data both for clinical and for population estimates of haematological parameters.

Adolescent↗
PubMed1977

Serum urate levels between ages 10 and 14: changes in sex trends.

Urate levels were assayed in sera of 292 subjects between 10 and 14 years of age identified through a probability sample of a natural population. The sex trends in serum urate concentrations characteristic of childhood were seen to continue into early adolescence, with girls maintaining slightly higher means. Between 10 and 14 years there was first an overlap of male and female values followed by a reversal of trends, with much higher means in boys. Serum urate concentrations peaked in girls at age 11 and gradually stabilized at lower levels. Boys, on the other hand, showed little age variation in serum urate at 10 and 11 years but by age 12 showed sharp upward trends which continued throughout adolescence. Since age and body weight are known to be important covariates of serum urate, boys were matched to girls of the same age and body weight. Significant sex differences in urate levels persisted (after matching) only for 14-year-old adolescents and thus at this age could not be ascribed to weight differentials. The study highlights a peripubertal phenomenon whose mechanism might be endocrine related.

Adolescent↗
PubMed1976

Population serum urate levels and their correlates. The Sherbrooke regional study.

A natural population has been studied for its serum urate levels and for host factors associated with these levels. Householdhood, ethnicity, drug and alcohol use were found to be negligible behavioral attributes with respect to population serum urate concentrations. Of interest among significant correlates of serum urate are smoking behavior, serum protein, creatinine, calcium and monocyte count. Predominant statistically significant host factors, however, are sex, body weight and age, body weight being linearly related in both sexes and age in females only.

Adult↗
PubMed1976

Use of values for calcium and protein in serum, and of a derived index obtained from a probability population sample.

We measured serum protein and calcium concentrations in 2340 individuals between 10 and 96 years of age from 900 families chosen by probability methods to give a representative population. These values were used to calculate an index, based on a regression analysis of serum protein on calcium, which was then treated as a new variable. Age-sex specific reference values and frequency distributions are presented for this index as well as for protein and calcium calculated by both parametric and nonparametric methods.

Adolescent↗