13 research outputs found
Hormonal determinants of successful aging in men
The average length of human life is currently 75 to 78 years and may increase to 85
years during the coming two decades, but it is not clear whether these additional
years will be satisfying to live. Most data indicate modest gain in the number of healthy
years lived but a far greater increase in years of compromised physicaL mental and
social function. The number of days of restricted activity and the number of
admissions to hospitals and nursing homes sharply increases after age 70. One U.S.
health interview survey indicates that. at present, more than 25 million aging people
suffer from physical impairment. whereas the number of people requiring assistance in
activities of daily living increases from 14% at age 65 to 75 to 45% in those over 85 years
old
The endocrinology of aging
Most aging individuals die from atherosclerosis, cancer, or dementia; but in the oldest old, loss of muscle strength resulting in frailty is the limiting factor for an individual's chances of living an independent life until death. Three hormonal systems show decreasing circulating hormone concentrations during normal aging: (i) estrogen (in menopause) and testosterone (in andropause), (ii) dehydroepiandrosterone and its sulphate (in adrenopause), and (iii) the growth hormone/insulin-like growth factor I axis (in somatopause). Physical changes during aging have been considered physiologic, but there is evidence that some of these changes are related to this decline in hormonal activity. Hormone replacement strategies have been developed, but many of their aspects remain controversial, and increasing blood hormone levels in aging individuals to those found during mid-adult life has not been uniformly proven to be safe and of benefit.</jats:p
Serum insulin-like growth factor binding protein-2 levels as an indicator of functional ability in elderly men
BACKGROUND: In a cross-sectional study in 403 healthy, independently
living elderly men (mean age 78 years), we determined which are the main
physiological determinants of functional ability in the elderly, and which
components of the somatotropic system contribute to the maintenance of
functional ability. METHODS: Functional ability was assessed by the number
of problems in activities of daily living and by a measure of physical
performance. Other physical characteristics included leg extensor
strength, bone mineral density of total body and proximal femur, and body
composition, including lean mass and fat mass. Serum insulin-like growth
factor (IGF)-I and its binding proteins (IGFBP) -1, -2 and -3
concentrations were all measured by RIA. RESULTS: Muscle strength was
related to a lower degree of disability. Further, it was positively
related to physical performance and bone mineral density (all P<0.001).
Fat mass influenced activities of daily living and physical performance
negatively and bone mineral density positively (all P<0.001). Serum
concentrations of IGF-I and IGFBP-3 were not related to any of the
physical characteristics. High serum IGFBP-2 concentrations were related
to a higher degree of disability (P<0.001), a lower physical performance
(P=0.006), muscle strength (P=0.002), bone mineral density of proximal
femur (P=0.007), lean mass and fat mass (both P<0.001). Serum insulin and
IGFBP-1 concentrations were independently, positively related to lean mass
(P=0.003) and fat mass (P<0.001). CONCLUSIONS: In independently living
elderly men, functional ability appears to be determined by muscle
strength (positive) and fat mass (negative). Low serum IGFBP-2
concentrations are a powerful indicator for overall good physical
functional status, probably inversely reflecting the integrated sum of
nutrition and the biological effects of growth hormone, IGF-I and insulin
Measures of bioavailable serum testosterone and estradiol and their relationships with muscle strength, bone density, and body composition in elderly men
In the present cross-sectional study of 403 independently living elderly
men, we tested the hypothesis that the decreases in bone mass, body
composition, and muscle strength with age are related to the fall in
circulating endogenous testosterone (T) and estrogen concentrations. We
compared various measures of the level of bioactive androgen and estrogen
to which tissues are exposed. After exclusion of subjects with severe
mobility problems and signs of dementia, 403 healthy men (age, 73-94 yr)
were randomly selected from a population-based sample. Total T (TT), free
T (FT), estrone (E1), estradiol (E2), and sex hormone-binding globulin
(SHBG) were determined by RIA. Levels of non-SHBG-bound T (non-SHBG-T), FT
(calc-FT), the TT/SHBG ratio, non-SHBG-bound E2, and free E2 were
calculated. Physical characteristics of aging included muscle strength
measured using dynamometry, total body bone mineral density (BMD), hip
BMD, and body composition, including lean mass and fat mass, measured by
dual-energy x-ray absorptiometry. In this population of healthy elderly
men, calc-FT, non-SHBG-T, E1, and E2 (total, free, and non-SHBG bound)
decreased significantly with age. T (total and non-SHBG-T) was positively
related with muscle strength and total body BMD (for non-SHBG-T,
respectively, beta = 1.93 +/- 0.52, P < 0.001 and beta = 0.011 +/- 0.002,
P < 0.001). An inverse association existed between T and fat mass (beta =
-0.53 +/- 0.15, P < 0.001). Non-SHBG-T and calc-FT were more strongly
related to muscle strength, BMD, and fat mass than TT and were also
significantly related to hip BMD. E1 and E2 were both positively,
independently associated with BMD (for E2, beta = 0.21 +/- 0.08, P <
0.01). Non-SHBG-bound E2 was slightly strongly related to BMD than total
E2. The positive relation between T and BMD was independent of E2. E1 and
E2 were not related with muscle strength or body composition. In summary,
bioavailable T, E1, total E2, and bioavailable E2 all decrease with age in
healthy old men. In this cross-sectional study in healthy elderly men,
non-SHBG-bound T seems to be the best parameter for serum levels of
bioactive T, which seems to play a direct role in the various
physiological changes that occur during aging. A positive relation with
muscle strength and BMD and a negative relation with fat mass was found.
In addition, both serum E1 and E2 seem to play a role in the age-related
bone loss in elderly men, although the cross-sectional nature of the study
precludes a definitive conclusion. Non-SHBG-bound E2 seems to be the best
parameter of serum bioactive E2 in describing its positive relation with
BMD
Luteinizing hormone and different genetic variants, as indicators of frailty in healthy elderly men
We investigated the possible clinical correlates between the serum LH
concentration and characteristics of frailty and determined the presence
and concentration of a genetic LH variant in an independently living
population of elderly men. After exclusion of subjects with severe
mobility problems and signs of dementia, 403 healthy men (aged 73-94 yr)
were randomly selected from a population-based sample. Total testosterone
(T), sex hormone-binding globulin (SHBG), and leptin were determined by
RIA. Non-SHBG-bound T was calculated. LH and the presence of the genetic
LH variant were measured using immunofluorometric assays. The
characteristics of frailty were leg extensor strength using dynamometry,
bone mineral density of total body and proximal femur, and body
composition, including lean mass and fat mass, measured by dual energy
x-ray absorptiometry. Disability was further assessed by the Modified
Health Assessment Questionnaire and by a measure of physical performance.
LH significantly increased with age and inversely correlated with T and
non-SHBG-bound T. LH was inversely related to muscle strength and lean
mass, and both relations were independent of T. LH was positively related
to self-reported disability (Modified Health Assessment Questionnaire);
12.5% of the study population was heterozygous for the LH variant allele.
T levels and the degree of frailty were not different in the wild-type LH
group compared with the heterozygote LH variant group. A significant
positive relation between LH and fat mass as well as leptin was only
present in the heterozygote LH variant group. In conclusion, serum LH
levels increases with age in independently living elderly men and
correlates inversely with a variety of indicators of frailty. The observed
relation between LH and frailty, independent of T, suggests that LH
reflects serum androgen activity in a different way than T, possibly
reflecting more closely the combined feedback effect of estrogen and
androgen. A difference in biological response between the two LH forms is
suggested, as a difference exists in the relation between LH and fat mass,
respectively, and leptin in the heterozygote LH variant subjects vs. the
wild-type LH subjects
SUGAR-DIP trial: Oral medication strategy versus insulin for diabetes in pregnancy, study protocol for a multicentre, open-label, non-inferiority, randomised controlled trial
Introduction In women with gestational diabetes mellitus (GDM) requiring pharmacotherapy, insulin was the established first-line treatment. More recently, oral glucose lowering drugs (OGLDs) have gained popularity as a patient-friendly, less expensive and safe alternative. Monotherapy with metformin or glibenclamide (glyburide) is incorporated in several international guidelines. In women who do not reach sufficient glucose control with OGLD monotherapy, usually insulin is added, either with or without continuation of OGLDs. No reliable data from clinical trials, however, are available on the effectiveness of a treatment strategy using all three agents, metformin, glibenclamide and insulin, in a stepwise approach, compared with insulin-only therapy for improving pregnancy outcomes. In this trial, we aim to assess the clinical effectiveness, cost-effectiveness and patient experience of a stepwise combined OGLD treatment protocol, compared with conventional insulin-based therapy for GDM. Methods The SUGAR-DIP trial is an open-label, multicentre randomised controlled non-inferiority trial. Participants are women with GDM who do not reach target glycaemic control with modification of diet, between 16 and 34 weeks of gestation. Participants will be randomised to either treatment with OGLDs, starting with metformin and supplemented as needed with glibenclamide, or randomised to treatment with insulin. In women who do not reach target glycaemic control with combined metformin and glibenclamide, glibenclamide will be substituted with insulin, while continuing metformin. The primary outcome will be the incidence of large-for-gestational-age infants (birth weight >90th percentile). Secondary outcome measures are maternal diabetes-related endpoints, obstetric complications, neonatal complications and cost-effectiveness analysis. Outcomes will be analysed according to the intention-to-treat principle. Ethics and dissemination The study protocol was approved by the Ethics Committee of the Utrecht University Medical Centre. Approval by the boards of management for all participating hospitals will be obtained. Trial results will be submitted for publication in peer-reviewed journals
Cortisol and Phosphate Homeostasis: Cushing’s Syndrome Is Associated With Reversible Hypophosphatemia
Objectives: The influence of hypercortisolism on phosphate homeostasis is relatively unknown. A few previous studies have reported on patients with Cushing’s syndrome (CS) with hypophosphatemia in whom serum phosphate normalized after initiation of treatment for CS. We aimed to investigate the prevalence of hypophosphatemia in CS, the association between the degree of hypercortisolism and serum phosphate and the change in serum phosphate after remission of CS. We compared the prevalence of hypophosphatemia in CS with the prevalence in the population-based Rotterdam Study (RS). Methods: Patients diagnosed with CS and treated at the Department of Endocrinology of Erasmus MC in the period of 2002-2020 were included and data was collected on age at diagnosis, sex, serum phosphate, calcium and potassium levels, kidney function and BMI. Using multivariate linear regression, we analyzed the association between 24h urinary free cortisol excretion (UFC) and serum phosphat
Brief report: Effects of dehydroepiandrosterone and atamestane supplementation on frailty in elderly men
Background: It has been suggested that the age-related decline of androgens in men plays a distinct role in the development of several aspects of frailty. Therefore, hormone replacement might improve the course of frailty by increasing lean body mass and muscle strength, decreasing fat mass, and improving the subjective quality of life. Objective: The objective of the study was to assess whether hormone replacement with dehydroepiandrosterone (DHEA) and/or atamestane might improve the course of frailty. Design: This was a double-blind, randomized, controlled trial. Setting: The study was conducted in the general community. Participants: Participants included 100 nonhospitalized, nondiseased, independently living men, aged 70 yr and over with low scores on strength tests. Seventeen participants did not complete the trial. Intervention: Subjects were randomly assigned to one of four intervention arms: atamestane (100 mg/d) and placebo, DHEA (50 mg/d) and placebo, a combination of atamestane (100 mg/d) and DHEA (50 mg/d), or two placebo tablets for 36 wk. Main Outcome Measures: Physical frailty was measured by means of a specific test battery, including isometric grip strength, leg extensor power, and physical performance. Results: The randomization was successful, and 83 (83%) men completed the intervention. There were no differences between the treatment arms and placebo group in any of the outcome measurements after intervention. Conclusions: The results of this double-blind, randomized trial do not support the hypothesis that hormone replacement with DHEA and/or atamestane might improve the course of frailty. Copyrigh
Endogenous hormones and carotid atherosclerosis in elderly men
The aging process is characterized by a number of gradual changes in
circulating hormone concentrations as well as a gradual increase in the
degree of atherosclerosis. The authors studied whether serum hormone
levels are related to atherosclerosis of the carotid artery in
independently living, elderly men. In 1996, 403 men (aged 73-94 years)
were randomly selected from the general population of Zoetermeer, the
Netherlands. Carotid artery intima-media thickness was determined. Serum
concentrations of testosterone; estrone; estradiol; dehydroepiandrosterone
and dehydroepiandrosterone sulfate; insulin-like growth factor I (IGF-I)
(total and free) and its binding proteins IGFBP-1, IGFBP-2, and IGFBP-3;
and leptin were measured. After the authors adjusted for age, serum
testosterone, estrone, and free IGF-I were inversely related to
intima-media thickness. The strength of these relations was as powerful in
subjects with as in those without prevalent cardiovascular disease. Serum
estradiol; dehydroepiandrosterone sulfate; total IGF-I, IGFBP-1, IGFBP-2,
and IGFBP-3; and leptin showed no association. These findings suggest that
endogenous testosterone, estrone, and free IGF-I levels may play a
protective role in the development of atherosclerosis in aging men
High IGFBP2 levels are not only associated with a better metabolic risk profile but also with increased mortality in elderly men
Objective: Serum IGF-binding protein 2 (IGFBP2) concentrations are reduced in obese humans and increase after a prolonged period of fasting. We investigated the association between IGFBP2 levels and mortality together with other factors that are related to IGFBP2, including the metabolic syndrome and physical function. Design: A prospective observational study at a clinical research center of 403 independently living elderly men (aged 73-94 years). Methods: Mortality was registered during 8.6 years of follow-up. Physical performance score (PPS), grip strength (GS), and bone minera