Urinary cortisol and muscle mass in Turkana men

Lukas, W; Campbell, Kenneth L.

doi:10.1002/ajhb.20402

Cited by 13 publications

(12 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the existence of nomadic and settled population subpopulations provides a contrast between genetically related groups that experience different ecological conditions (Little et al, 1999b). Previous results indicating both higher cortisol (Lukas et al, 2005) and declining adiposity with age suggest that the nomadic males represented here are under additional nutritional stress compared to the settled sample.…”

mentioning

confidence: 75%

See 1 more Smart Citation

Age‐related changes in testosterone and SHBG among Turkana males

Leslie

Campbell

2005

American J Hum Biol

View full text Add to dashboard Cite

To determine age-related changes in biologically available testosterone (T) among men in a subsistence society and their relationship to energetic status, T, sex hormone binding globulin (SHBG) and anthropometric measures were compared among nomadic and settled Turkana pastoralists of northern Kenya. Hormonal measures were available for 104 nomadic men and 72 settled men, estimated ages 20-90 years. Comparison of the two subpopulations revealed significantly higher blood T (32.7+/- 15.1 vs. 23.4+/-15.2 nM) and SHBG (53.8+/- 19.5 vs. 39.7+/- 20.nM) but not free testosterone index (FTI) (65.6+/- 39.3 vs.66.3+/- 45.9) among the nomads. Total blood T did not exhibit a significant linear decline with age in either subgroup, while SHBG values showed a significant linear increase among the nomads. When controlled for energetic status, FTI showed a significant decrease with age among the nomads, but not the settled males. Total blood T was negatively associated with waist circumference among the nomads, but not the settled males. FTI showed a marginally significant negative association with waist circumference, suprailiac skinfold, and % body fat among the nomads but no associations with body composition among the settled group. These results add additional evidence that T is related to energetic status under conditions of negative energy balance and suggest that cross-population variation in the slope of age-related declines in free serum T and salivary T may be related to energetic status through the effects of SHBG.

show abstract

mentioning

confidence: 75%

“…An inverse association between urinary cortisol and MPBA among the Turkana nomads (Lukas et al, 2005) clearly suggests a catabolic state among the Turkana nomads. Nindl et al (1996) suggest that fat remains in the arms and legs until weight loss is extreme and abdominal fat is depleted.…”

Section: Hormones and Energetic Statusmentioning

confidence: 97%

Age‐related changes in testosterone and SHBG among Turkana males

Leslie

Campbell

2005

American J Hum Biol

View full text Add to dashboard Cite

show abstract

“…Together with evidence for negative energy balance among the nomads and positive energy balance among the settled males Lukas et al, 2005), the current findings suggest that Turkana men may experience significant changes in the HPG axis as a result of weight changes associated with environmental fluctuation.…”

Section: Discussionmentioning

confidence: 78%

“…Not only do the Turkana experience chronic undernutrition (Galvin and Little, 1999), but the presence of two genetically similar subpopulations that differ in their ecological context provides an additional contrast. Earlier results documenting lower levels of adiposity and increased urinary cortisol (Lukas et al, 2005) among the nomadic males, compared to their settled counterparts, provide evidence that the nomads are in a catabolic state while the settled males are in positive energy balance.…”

Section: Introductionmentioning

confidence: 91%

Age‐related patterns of urinary Gonadotropins (FSH and LH) and E‐3‐G as measures of reproductive function among Turkana Males of Northern Kenya

Leslie¹,

Campbell²

2006

Biodemography and Social Biology

View full text Add to dashboard Cite

To determine age-related patterns of gonadotropins and their relationship to energetic status in a subsistence population we analyzed urinary FSH, LH, and estrone-3-glucuronide (E-3-G) along with anthropometric measures among Turkana males of northern Kenya. Subjects were 134 nomadic and 109 settled males ages 20 to 80+. FSH, LH and E-3-G were significantly higher among the settled, compared to nomadic, males. LH, but not FSH, showed a significant increase across 10 year age groups among all the men. E-3-G increased across age groups only among the settled males. Controlled for age, FSH was inversely related to measures of fat free and body mass among the settled men. These findings suggest an unusual age profile of gonadotropins and estrogen metabolites that may reflect the impact of fluctuating food availability. More research is needed to address the impact of energetic and social factors on the male reproductive axis among energetically stressed populations.

show abstract

“…Cortisol, the so-called stress hormone, can also be measured using urine samples. In addition to its role in the management of physiological challenges, cortisol has been shown to be associated with gonadal hormone levels (Lukas et al 2005;Nepomnaschy et al 2004) and can be linked to reproductive mechanisms.…”

Section: Urine Samplesmentioning

confidence: 99%

Taking the Lab to the Field: Monitoring Reproductive Hormones in Population Research

Valeggia¹

2007

Population & Development Rev

View full text Add to dashboard Cite

The incorporation of biological measures in social science research allows for the development of robust models, with greater explanatory power. By analyzing the underlying proximate causes of fertility and mortality, biodemographers have been able to model demographic patterns more accurately. Recent technological advances are making possible the analysis of biological samples collected using minimally invasive methods. Methods and techniques are discussed that can be used for estimating hormonal, particularly reproductive hormone, levels in large-scale population studies in which thousands of samples could be collected. Sample collection methods and techniques reviewed include blood spots, urine samples, and saliva samples. The collection of biological samples is associated with serious ethical concerns. The article discusses the issue of asymmetries in technology between developing and developed countries, emphasizing the need for capacity building and information transfer. Illustrative contributions of biological data are presented. Copyright 2007 The Population Council, Inc..

show abstract

Urinary cortisol and muscle mass in Turkana men

Cited by 13 publications

References 25 publications

Age‐related changes in testosterone and SHBG among Turkana males

Age‐related changes in testosterone and SHBG among Turkana males

Age‐related patterns of urinary Gonadotropins (FSH and LH) and E‐3‐G as measures of reproductive function among Turkana Males of Northern Kenya

Taking the Lab to the Field: Monitoring Reproductive Hormones in Population Research

Contact Info

Product

Resources

About