Organochlorine Exposure in Relation to Timing of Natural Menopause
Organochlorine Exposure in Relation to Timing of Natural Menopause
This study will examine whether exposure to organochlorines (certain chemicals such as PCBs
 and DDE, used in pesticides or other industrial applications) is related to age at natural
 menopause. It is known, for example, that smokers experience menopause 1 to 2 years earlier
 than do non-smokers. This study will look for a similar association between organochlorine
 exposure and menopause. It will also look for possible associations between specific factors,
 such as pregnancy history and weight change, and changes over time in blood organochlorine
 levels.

 Women who participated in the North Carolina Infant Feeding Study between 1978 and 1982 are
 eligible for this study. Participants will be interviewed over the phone for information
 about their reproductive and menstrual history, as well as additional information that may be
 related to age and menopausal status. Specifically, the interview will cover the following
 areas: 1) pregnancy and breastfeeding history; 2) menstrual periods and menopause; 3) use of
 birth control pills and hormone replacement therapy; 4) surgeries on the uterus or ovaries,
 such as hysterectomy or oophorectomy, or both; 5) smoking and alcoholic beverage consumption;
 6) physical activity; 7) weight history; and 8) medical history. About one-half of the
 participants will have a blood sample drawn for analysis of the reproductive hormones FSH
 (follicle-stimulating hormone) and LH (leuteinizing hormone) and of DDE and PCB levels.
Smoking has been shown in many studies to be associated with a 1-2 year decrease in age at
 natural menopause. However, relatively little is known about the effect of other potential
 toxicants, including organochlorines such as polychlorinated biphenyls (PCBs), and 1, 1
 dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p -DDE, referred to subsequently as DDE). We
 will assess timing of menopause among women who participated in the North Carolina Infant
 Feeding Study (total n = 865). Recruitment for this study was conducted between 1978 and
 1982. PCB and DDE levels were analyzed in blood and breast milk samples around delivery and
 after pregnancy. The median age of the women as of March, 2002, is 50 years. Data will be
 collected in a telephone interview focusing on reproductive and menstrual history with
 additional information collected on demographic, social and behavioral factors that could
 affect timing of menopause. A blood sample will be collected from approximately 50% of
 participants based on sampling strata that involve criteria relating to age and menopausal
 status. Follicle stimulating hormone and luteinizing hormone will be measured in these
 samples in order to classify menopausal status of women who had undergone hysterectomy with
 retention of at least one ovary, women who are currently using hormone replacement therapy
 whose use began while still having periods, and women who report very short, very long, or
 irregular menstrual cycle lengths during the past 12 months. PCB and DDE levels will also be
 determined in these samples, allowing us to assess the correlation between current and
 baseline (1978-1982) PCB and DDE measures. The purpose of this study is to assess the
 association between the baseline organochlorine measurements and timing of natural menopause.
 A secondary aim will be to conduct exploratory analyses of the association between specific
 factors (e.g., pregnancy history, weight change) and rate of change in organochlorine levels.
-  INCLUSION AND EXCLUSION CRITERIA:

 There will be no exclusions based on age, ethnicity or race/ethnicity. Participants who are
 unable to complete a telephone interview because of chronic illness (including cognitive
 impairment) or language or hearing difficulties will not be eligible.

 There are 8 women in the cohort whose study children are known to have died. We will
 exclude these women from this follow-up study.

 This leaves 857 women that are eligible for tracing the follow-up interview.