Ken R. Smith

Association between telomere length in blood and mortality in people aged 60 years or older

During normal ageing, the gradual loss of telomeric DNA in dividing somatic cells can contribute to replicative senescence, apoptosis, or neoplastic transformation. In the genetic disorder dyskeratosis congenita, telomere shortening is accelerated, and patients have premature onset of many age-related diseases and early death. We aimed to assess an association between telomere length and mortality in 143 normal unrelated individuals over the age of 60 years. Those with shorter telomeres in blood DNA had poorer survival, attributable in part to a 3.18-fold higher mortality rate from heart disease (95% CI 1(.)36-7.45, p=0.0079), and an 8.54-fold higher mortality rate from infectious disease (1.52-47.9, p=0.015). These results lend support to the hypothesis that telomere shortening in human beings contributes to mortality in many age-related diseases.

PSYCHOLOGICAL RESPONSES TO BRCA1 MUTATION TESTING: PRELIMINARY FINDINGS

The short-term psychological responses of 60 adult women tested for a BRCA1 gene mutation associated with a high risk of breast and ovarian cancer were investigated. Participants were members of a large kindred enrolled in an ongoing prospective study of the psychosocial impact of genetic testing. Initial results from participants who completed both the pretest baseline and the 1-2 week posttest follow-up interviews are reported. Gene mutation carriers manifested significantly higher levels of test-related psychological distress, as measured by the Impact of Event Scale, when compared with noncarriers. The highest levels of test-related distress were observed among mutation carriers with no history of cancer or cancer-related surgery. Although general distress (state anxiety) declined after testing, carriers were more distressed than noncarriers at follow-up.

Phantom of the area: poverty-area residence and mortality in the United States.

OBJECTIVES The purpose of the study was to conduct a national multivariate analysis on poverty-area residence and mortality in the United States. METHODS Proportional hazards analyses were performed of the effect of poverty-area residence on the risk of mortality among adult examinees in the 1971 through 1974 National Health and Nutrition Examination Survey who were followed through 1987. RESULTS Poverty-area residence was associated with significantly elevated risk of all-cause mortality (rate ratio = 1.78, 95% confidence interval = 1.33, 2.38) and some cause-specific mortality among those aged 25 through 54 years, but not among those aged 55 through 74 years, at baseline after adjustment for several individual and household characteristics. CONCLUSIONS Residence in poverty areas contributes to socioeconomic gradients in mortality among nonelderly adults in the United States.

Genetic testing for a BRCA1 mutation: Prophylactic surgery and screening behavior in women 2 years post testing

Mutations in the BRCA1 gene are associated with an increased risk of breast and ovarian cancer in carrier women. An understanding of behavioral responses to BRCA1 mutation testing by mutation carriers and non‐carriers is important to guide the clinical application of this new technology. This study examined the utilization of genetic testing for a BRCA1 mutation in high‐risk individuals and the response of tested women with respect to interventions for early cancer detection and prevention. This study assessed the utilization of genetic testing for both men and women in a large kindred and the behavioral responses by women with respect to use of health care interventions during the 2 years following testing. Participants were offered BRCA1 mutation testing. Surveillance behaviors related to breast and ovarian cancer were assessed by computer‐assisted telephone interviews at baseline (prior to genetic counseling and testing), 1–2 weeks, 4–6 months, 1 and 2 years after the provision of test results. Mutation carriers, non‐carriers, and individuals of unknown mutation status were compared to determine the impact of test results. Utilization of genetic testing for both men and women are reported and, for women, mammography, breast self‐exam, clinical breast exam, mastectomy, oophorectomy, transvaginal ultrasound, and CA125 screening were assessed. Of those fully informed of the opportunity for testing, 55% of the women and 52% of the men pursued genetic testing. With respect to mammography for women 40 years and older, 82% of mutation carriers obtained a mammogram in each year following testing compared to 72% of non‐carrier women the first year and 67% the second year. This mammography utilization represents a significant increase over baseline for both mutation carriers and non‐carriers. Younger carrier women also significantly increased their mammography utilization from baseline. Overall, 29% of the carrier women did not obtain a single mammogram by 2 years post‐testing. At 2 years, 83% of the carrier women and 74% of the non‐carriers reported adherence to recommendations for breast self‐exam and over 80% of carrier women had obtained a clinical breast examination each year following testing. None of the carrier women had obtained a prophylactic mastectomy by 2 years after testing, although 11% were considering this procedure. Of carrier women 25 years of age and older who had at least one intact ovary at the time of testing, 46% of carriers had obtained an oophorectomy 2 years after testing, including 78% of women 40 years of age and older. The majority of carrier women (73%) had discussed their genetic test results with a medical doctor or health care provider. Our results indicate utilization of genetic testing by a majority of high‐risk individuals who received information about testing. Both carriers and non‐carriers increased their utilization of mammography and breast self‐exam following testing. Oophorectomy was obtained by a large proportion of carrier women in contrast to mastectomy which was not utilized within the first 2 years following testing.

Marital Transitions, Poverty, and Gender Differences in Mortality.

Studies of the causes of marital status differentials in mortality have generally concluded that marriage serves to protect individuals from premature death. The analyses presented in this article extend this work by examining how recent marital transitions and associated levels of economic status affect mortality. With a health production model and micro-level data from the Panel Study of Income Dynamics [for the United States] sex-specific proportional hazard rate models of death are estimated as a function of recent marital transitions and poverty status as well as other sociodemographic characteristics. The results indicate that recent spells of poverty increased the hazard of dying for both men and women while recent marital status transitions altered the hazard of dying only for men. (EXCERPT)

Mixed land use and walkability: Variations in land use measures and relationships with BMI, overweight, and obesity.

Few studies compare alternative measures of land use diversity or mix in relationship to body mass index. We compare four types of diversity measures: entropy scores (measures of equal distributions of walkable land use categories), distances to walkable destinations (parks and transit stops), proxy measures of mixed use (walk to work measures and neighborhood housing ages), and land use categories used in entropy scores. Generalized estimating equations, conducted on 5000 randomly chosen licensed drivers aged 25-64 in Salt Lake County, Utah, relate lower BMIs to older neighborhoods, components of a 6-category land use entropy score, and nearby light rail stops. Thus the presence of walkable land uses, rather than their equal mixture, relates to healthy weight.

Separate but lethal: the effects of economic segregation on mortality in metropolitan America.

The increase in income inequality in the United States over the past 20 years has been accompanied by a pronounced increase in economic segregation in urban areas. No research to date has analyzed the potential effects of such spatial segregation on mortality. To investigate these effects, the mortality experience of respondents aged 30 years and older on the 1986-94 National Health Interview Surveys residing in any one of 30 large metropolitan areas in the United States was analyzed. Concentrated poverty was associated with significantly elevated risk of mortality, even after controlling for individual household income. Concentrated affluence showed a consistent, protective effect only among the elderly. The effects were most pronounced among the poor, but were not confined to them. Urban planning should take into account the effects associated with economic residential segregation.

Fertility and post‐reproductive longevity

Abstract We examine the effects of reproduction on longevity among mothers and fathers after age 60. This study is motivated by evolutionary theories of aging and theories predicting social benefits and costs of children to older parents. We use the Utah Population Database, that includes a large genealogical database from the Utah Family History Library. Cox proportional hazard models based on 13,987 couples married between 1860–1899 indicate that women with fewer children as well as those bearing children late in life live longer post‐reproductive lives. As the burdens of motherhood increase, the relative gains in longevity of late fertile women increase compared to their non‐late fertile counterparts. Husbands’ longevity is less sensitive to reproductive history, although husbands have effects that are similar to those of their wives during the latter marriage cohort. We find some support for predictions based on evolutionary principles, but we also find evidence that implicates a role for shared marital environments.

Linked lives, dependent demise? Survival analysis of husbands and wives

Past research has found that married individuals have substantially lower risks of mortality than their single counterparts. This paper examines how household characteristics affect spouses’ risks of mortality. A paired hazard rate model is estimated and tests are made to ascertain whether the estimated coefficients associated with risk factors differ between husbands’ and wives’ equations. Cigarette smoking, risk-avoidance behavior, poverty, and children are found to affect wives’ and husbands’ mortality in similar ways. Divorce, which can be interpreted as the termination of this shared household environment, is found to affect spouses differently.

Is there a trade-off between fertility and longevity? A comparative study of women from three large historical databases accounting for mortality selection.

Frontier populations provide exceptional opportunities to test the hypothesis of a trade‐off between fertility and longevity. In such populations, mechanisms favoring reproduction usually find fertile ground, and if these mechanisms reduce longevity, demographers should observe higher postreproductive mortality among highly fertile women. We test this hypothesis using complete female reproductive histories from three large demographic databases: the Registre de la population du Québec ancien (Université de Montréal), which covers the first centuries of settlement in Quebec; the BALSAC database (Université du Québec à Chicoutimi), including comprehensive records for the Saguenay‐Lac‐St‐Jean (SLSJ) in Quebec in the nineteenth and twentieth centuries; and the Utah Population Database (University of Utah), including all individuals who experienced a vital event on the Mormon Trail and their descendants. Together, the three samples allow for comparisons over time and space, and represent one of the largest set of natural fertility cohorts used to simultaneously assess reproduction and longevity. Using survival analyses, we found a negative influence of parity and a positive influence of age at last child on postreproductive survival in the three populations, as well as a significant interaction between these two variables. The effect sizes of all these parameters were remarkably similar in the three samples. However, we found little evidence that early fertility affects postreproductive survival. The use of Heckmans procedure assessing the impact of mortality selection during reproductive ages did not appreciably alter these results. We conclude our empirical investigation by discussing the advantages of comparative approaches. Am. J. Hum. Biol., 2009.