Biomedical subjects

M D Sammel

Publications and source records attributed to M D Sammel.

4 recordsLinked to original sources

PubMed2001

Racial differences in sex hormone levels in women approaching the transition to menopause.

OBJECTIVE: Evaluate racial differences in reproducibility of hormone levels over time (estradiol, DHEAS, FSH, and testosterone) while adjusting for covariates previously identified as relevant in the study population. DESIGN: Longitudinal cohort study. SETTING: Healthy, late-reproductive-age women in a community-based sample. PATIENT(S): African American and Caucasian women identified by random digit dialing. INTERVENTION(S): Hormone levels measured in the early follicular phase of the menstrual cycle four times over 9 months. A multivariate, linear mixed model estimated effects on hormone levels of race, age at enrollment, age at menarche, number of pregnancies, current smoking, alcohol consumption, body mass index (BMI), waist/hip ratio (WHR), and menstrual cycle length. MAIN OUTCOME MEASURE(S): Follicular plasma levels of estradiol, FSH, DHEAS, and testosterone. RESULT(S): African American but not Caucasian women had significantly lower levels of estradiol and DHEAS with increasing age. African American but not Caucasian women had significantly decreased levels of estradiol and significantly increased levels of DHEAS with increasing BMI. No racial differences in reproducibility of hormone measures were found. CONCLUSION(S): There are racial differences in associations of hormone levels with age and BMI in late reproductive age women. Further study is needed to replicate these findings and to determine the relationships of these hormonal associations with menopausal symptoms.

Adult↗

PubMed2000

Digit effects produced by prenatal exposure to antiepileptic drugs.

The hypothesis tested was that digit anomalies among individuals exposed in utero to antiepileptic drugs (AED) are best identified by a systematic search, including radiographs and dermatoglyphics, rather than relying only on visual inspection. A systematic search was made for five types of digit abnormalities in 46 AED-exposed individuals ages 5-29 years in comparison with controls: visible anomalies, size of fingernails, dermal ridge patterns, length of metacarpals and phalanges, and qualitative changes in the distal phalanges. Among the AED-exposed, nail size was not decreased. However, there was a 10.8% frequency of digit anomalies, a 12% frequency of three or more arch patterns, and significant shortening and qualitative changes in the distal phalanges, all of which are consistent with the fetal effects of AED. Among the 42 individuals who underwent all evaluations, 14.3% had two or more of these abnormalities, most of which would not be identified by clinical inspection. This frequency is much higher in these AED-exposed individuals than in the general population. Radiographs in 13 individuals over a period of several years showed that the changes in the phalanges and metacarpals persisted.

Abnormalities, Drug-Induced↗

PubMed1996

Latent variable models with fixed effects.

We discuss latent variable models that allow for fixed effect covariates, as well as covariates affecting the latent variable directly. Restricted maximum likelihood and maximum likelihood are used to estimate model parameters. A generalized likelihood ratio test can be used to test significance of the covariates effecting the latent outcomes. Special cases of the proposed model correspond to factor analysis, mixed models, random effects models, and simultaneous equations. The model is applied to birth defects data, where continuous data on the size of infants who were exposed to anticonvulsant medications in utero are compared to controls.

Algorithms↗

PubMedDate not supplied

Hot flashes in the late reproductive years: risk factors for Africa American and Caucasian women.

Hot flashes are a primary reason that midlife women seek medical care, but there is little information about the onset or the predictors of hot flashes in the years before the menopause. This study examines women's experience of hot flashes in the late reproductive years, comparing African American and Caucasian women, and identifies hormonal, behavioral, and environmental risk factors for hot flashes associated with ovarian aging. Data are from a population-based prospective cohort study of ovarian aging in women who were ages 35--47, in general good health, and had regular menstrual cycles at study enrollment. Hot flashes were assessed by subject report in a structured interview at the first follow-up period and correlated highly with previous prospective daily ratings of hot flashes (p = 0.0001). Blood samples were obtained in the first 6 days of the menstrual cycle in two consecutive cycles at enrollment and two consecutive cycles at follow-up. Predictor variables include hormone measures, structured interview, and standard questionnaire data. Thirty-one percent of the sample (n = 375) reported hot flashes (mean age 41 years). In bivariate analysis, more African American than Caucasian women reported hot flashes (38% vs. 25%, p = 0.01). Significant predictors of hot flashes in the final multivariable logistic regression model were higher follicle-stimulating hormone (FSH) levels (odds ratio [OR] 3.19), anxiety (OR 1.06), baseline menopausal symptoms (OR 4.91), alcohol use (OR 1.09), body mass index (BMI) (OR 1.04), and parity (OR 1.20). Race did not predict hot flashes after adjusting for these variables. Hot flashes commonly occur before observable menstrual irregularities in the perimenopause and are associated with both hormonal and behavioral factors. The association of hot flashes with increased body mass (BMI) challenges the current "thin" hypothesis and raises important questions about the role of BMI in hormone dynamics in the late reproductive years.

Adult↗