Age-dependent changes in body composition in postmenopausal Japanese women: relationship to growth hormone secretion as well as serum levels of insulin-like growth factor (IGF)-I and IGF-binding protein-3

Circulating IGFBP-3 and Interleukin 6 as Predictors of Osteoporosis in Postmenopausal Women: A Cross-Sectional Study

Objective. To explore the relationship between circulating IGFBP-3, IL-6, and bone mineral density and the potential diagnostic role of circulating IGFBP-3 and IL-6 in postmenopausal women with osteoporosis. Methods. Eighty-five postmenopausal women at Soochow University’s First Affiliated Hospital, Osteoporosis and Menopause Clinics, were recruited. Forty-five of 85 women were diagnosed with osteoporosis. Circulating IL-6, PTH, 1,25(OH)2D3, osteocalcin (OST), IGF-1, IGFBP-3, and bone mineral density (BMD) of the lumbar spine (LS) and femoral neck (FN) were measured in 40 ordinary and 45 osteoporotic women. A simple regression analysis calculated the correlation between age, BMD, IL-6, and IGFBP-3. Multiple stepwise regression analyses were conducted to determine which variables were independently related to BMD. The potential role of IGFBP-3 and IL-6 in the diagnosis of postmenopausal osteoporosis was predicted using the area under the receiver operating characteristic curve (ROC, AUC). Results. Age, years since menopause, and circulating IL-6, PTH, and IGFBP-3 were significantly higher in the osteoporosis group compared to the normal group. Osteoporotic women had substantially lower BMDs of the LS and FN than normal women. Age-related increases were found for IGFBP-3 and IL-6, whereas age-related decreases were observed for LS/FN BMD. IGFBP-3 and IL-6 were both negatively correlated with LS and FN BMD. Stepwise multiple regression analysis showed that IGFBP-3 and IL-6 were strong predictors of BMD in postmenopausal women. AUC cut-off values (IGFBP-3: 3.65, IL-6: 0.205) were best evaluated for the diagnosis of postmenopausal women with osteoporosis, and the AUC for circulating IGFBP-3 and IL-6 were 0.706 (95% CI 0.594–0.818) and 0.685 (95% CI 0.571–0.798), respectively. Conclusion. In this cross-sectional study of postmenopausal women, IGFBP-3 and IL-6 were negatively related to BMD. Circulating IGFBP-3 and IL-6 might be essential predictors of postmenopausal osteoporosis and can help predict osteoporotic fracture.

Higher circulating levels of IGF-1 are associated with longer leukocyte telomere length in healthy subjects

Mutations that inhibit the insulin-like growth factor-1 (IGF-1) extend the lifespan of worms, flies and mice. However, it appears that relatively low circulating levels of IGF-1 in humans are associated with aging-related diseases and diminished longevity. As leukocyte telomere length (LTL) is ostensibly a biomarker of human aging, we examined the relationship between LTL and blood IGF-1 in a healthy cohort. Our sample comprised 476 healthy, unrelated Caucasians (208 men and 268 women), aged 16-104 years, living in the West Coast of Southern Italy. We measured LTL by Southern blots and IGF-1 by enzyme-linked immunoassay. Both IGF-1 and LTL diminished with age (IGF-1, r=-0.601, P<0.001; LTL, r=-0.706, P<0.001). Age-adjusted LTL was positively associated with IGF-1 level throughout the age range of the cohort (r=0.270, P<0.001). IGF-1 accounted for about 10% of the inter-individual variation in LTL over and above the effect of age. Our findings suggest that both circulating IGF-1 and LTL are indices of healthy aging in humans. Further research will be necessary to establish whether LTL will ultimately be used in clinical settings as an index of healthy aging.

Associations of adiposity from childhood into adulthood with insulin resistance and the insulin-like growth factor system: 65-year follow-up of the Boyd Orr Cohort

CONTEXT

One metabolic pathway through which adiposity influences disease risk may be via alterations in insulin and IGF metabolism.

OBJECTIVE

Our objective was to investigate associations of adiposity at different stages of life with insulin and the IGF system.

DESIGN, SETTING, AND PARTICIPANTS

The study was a 65-yr follow-up of 728 Boyd Orr cohort participants (mean age, 71 yr) originally surveyed between 1937 and 1939.

MAIN OUTCOMES

Outcomes included homeostasis model assessment of insulin resistance, total IGF-I and IGF-II, IGF binding protein (IGFBP)-2, and IGFBP-3 in adulthood.

RESULTS

Childhood body mass index (BMI) was weakly inversely related to adult IGF-I (coefficient per BMI sd, -3.4 ng/ml; 95% confidence interval, -7.3 to 0.5; P = 0.09). IGF-II (but not IGF-I) increased with higher current fat mass index (coefficient, 26.1 ng/ml; 95% confidence interval, 4.6 to 47.6; P = 0.02) and waist-hip ratio (30.0 ng/ml; 9.4 to 50.5; P = 0.004). IGFBP-2 decreased by 21.2% (17.2 to 24.9; P < 0.001), and homeostasis model assessment of insulin resistance increased by 38.8% (28.9 to 49.6; P < 0.001) per sd higher adult BMI. Among thin adults (BMI tertiles 1 and 2), IGFBP-2 was positively, and insulin resistance was inversely, associated with childhood BMI.

CONCLUSION

There was only weak evidence that associations of childhood BMI with chronic disease risk may be mediated by adult IGF-I levels. Circulating IGFBP-2 in adulthood, a marker for insulin sensitivity, was inversely associated with current adiposity, but overweight children who became relatively lean adults were more insulin sensitive than thinner children. The findings may indicate programming of later insulin sensitivity and consequently IGFBP-2 levels in response to childhood adiposity. The role of IGF-II in obesity-related chronic diseases warrants additional investigation.

Insulin-like growth factor-I and mineral metabolism markers in children with idiopathic decrease in bone mass

OBJECTIVE

The aim of the study was to determine whether the serum concentration of insulin-like growth factor-I (IGF-I) and its binding protein-3 (IGFBP-3) correlates with the mineral metabolism markers in children with idiopathic decrease in bone mass.

PATIENTS AND METHODS

The study comprised 62 patients aged 6-18 years, including 42 with idiopathic decrease in bone mineral density (20 with osteoporosis and 22 with osteopenia) and 20 control children. Osteoporosis and osteopenia were diagnosed on the basis of complex clinical, densitometric and biochemical examinations (in all patients secondary causes of the decreased bone mass were excluded). Serum concentration of IGF-I was determined with radioimmunoassay and IGFBP-3 using immunoradiometry.

RESULTS

The children with osteoporosis and osteopenia were found to have mean IGF-I concentration statistically significantly lower than the controls (548 and 645 v. 819 ng/ml, respectively; p<0.05). Moreover, IGF-I correlated positively with total and spinal bone mineral density. In children with osteoporosis there was also a significant relationship between IGF-I and pyridinoline and deoxypyridinoline in urine.

CONCLUSIONS

Lower serum IGF-I concentration together with higher bone resorption and low bone mineral density reveal involvement of this growth factor in the development of idiopathic decrease of bone mass in children.

Rapidly exchangeable pool study of zinc in free-living or institutionalized elderly women

OBJECTIVE

We evaluated the effect of age and institutionalization on zinc metabolism by using a stable isotope technique.

METHODS

This was a randomized case-control study. Three groups were recruited: nine young women (group 1, ages 36+/-1 y) as controls, nine free-living elderly women (group 2, ages 72+/-2 y), and nine institutionalized women (group 3, ages 73+/-2 y). Only women were recruited to obtain homogeneous groups. The study was set in a Valence hospital (France) in the geriatric department (headed by Dr. Ferry). The experimental design of the study was reviewed and approved by the local ethical committee, and all participants signed a consent form. No subject dropped out of the study. A zinc stable isotope label (0.73 mg of (70)Zn) was injected intravenously into patients and measured by inductively coupled plasma mass spectrometry.

RESULTS

Decay curves of the plasma (70)Zn followed a one-compartment kinetic leading to the determination of one pool. The size of this pool suggested that it corresponded to the liver compartment. The size of this pool was significantly smaller in elderly people. (70)Zn plasma resident time was significantly longer in elderly individuals, and shorter in institutionalized than in free-living elderly subjects.

CONCLUSION

These data suggest that the zinc metabolism of elderly women is related to lifestyle or its consequences and to age. Moreover, we have demonstrated that kinetic studies using stable isotopes of zinc can provide novel information on exchangeable zinc pools in clinical situations.

Body composition, visceral fat distribution and fat oxidation in postmenopausal women using oral or transdermal oestrogen

OBJECTIVES

The aim of this study was to observe hysterectomized postmenopausal women (without progestogen, which could interfere in the results), using oral-conjugated oestrogen 0.625 mg daily (n=13) or 17beta-estradiol transdermal patches delivering 50 microg daily (n=10) during 12 months, and to evaluate the treatment effects on body composition, visceral fat distribution, energy expenditure and substrate oxidation.

METHODS

We studied 23 postmenopausal women using oral-conjugated oestrogen (Premarin) 0.625 mg daily (n=13) or transdermal oestrogen patches (Systen TTS) 50 microg daily (n=10). Body composition was measured by DEXA, visceral adipose tissue areas were measured by abdominal computed tomography, and energy expenditure, fat oxidation and carbohydrate oxidation were measured by indirect calorimetry (Deltatrac Metabolic Monitor).

RESULTS

There were: (1) a decrease in IGF-I and an increase in GH levels in the oral group and no change in the transdermal group; (2) a increase in lean body mass in the transdermal group and a decrease in the oral group; (3) a increase in total body fat mass in the oral group and no change in the transdermal group; (4) an increases in total bone mass and in total bone mineral density in the transdermal group and no change in the oral group; (5) an increase in lipid oxidation in the transdermal group and a decrease in the oral group, and (6) no significantly change about weight, visceral adipose tissue areas and energy expenditure in both groups.

CONCLUSIONS

The administration route of oestrogen replacement therapy in postmenopausal women confers distinct and divergent effects on body composition and substrate oxidation during 12-months treatment.

Serum Sex Hormones, IGF-1, and IGFBP3 Exert a Sexually Dimorphic Effect on Lean Body Mass in Aging

BACKGROUND

Endogenous and exogenous sex hormones affect changes in body composition during aging via independent and dependent effects on the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and associated binding proteins (BP).

METHODS

Fasting serum IGF-1, IGFBP3, testosterone, estrone, and sex hormone binding globulin were analyzed in 48 women on hormone replacement (HRT) (unopposed oral estrogen, HRT+, 74.0 +/- 6 years), 135 women not on HRT (HRT-, 77.3 +/- 7 years), and 128 healthy men (men, ). Total lean body mass (LBM) and total fat were measured by dual energy X-ray absorptiometry.

RESULTS

Total LBM decreased with age in all groups (p = .05). LBM was greater, and IGF-1, IGFBP3, and testosterone were lower in HRT+ versus HRT- women (p = .02, p = .01, p = .04, and, respectively). LBM in men was positively related to IGF-1 (p = .02) and testosterone (p < .01), whereas LBM was associated with IGFBP3 (p = .04) and total fat (p < .001) in female HRT+ and total fat (p < .01) in HRT- women. IGF-1 decreased with age in men and HRT- women (p < .01) but did not decrease in HRT+ women. Total fat significantly decreased across age (p < .05). Controlling for age and HRT, the rate of decrease in fat was slower in men versus women (p = .02). IGFBP3 decreased in all groups across age (p < .01), and the ratio of IGF-1 to IGFBP3 decreased faster in men compared to HRT+ and HRT- women (p = .02).

CONCLUSIONS

Our data indicate divergent influences of sex steroids, IGF-1, and IGFBP3 on age-related changes in LBM in healthy elderly men and women.

Analysis of the human growth hormone receptor and IGF-I coding sequences in children with growth disorders

Analysis of GHR and IGF-I coding sequences in 47 children with normal serum levels of GH, low IGF-I and growth disorders generally did not show mutation in the genes studied. Only one boy had a mutation located in the fifth exon of the GHR gene (C-->T in codon 88). This suggests that the growth disorders in this group of children might be due to a defect in a DNA region regulating expression of the GHR and IGF1 genes or genes involved in their regulation.

Dietary soy and fats in relation to serum insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 levels in premenopausal Japanese women

Circulating levels of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) have each been associated with premenopausal breast cancer risks. We analyzed data from a cross-sectional study of 261 premenopausal Japanese women aged 20-54 yr with adequate nutritional status to evaluate the relationships between concentrations of IGF-1 and IGFBP-3 in serum and dietary intakes of soy, fats and other nutrients. Diet was assessed by a semiquantitative food frequency questionnaire. There was no significant correlation between soy product as well as soy isoflavone intake and serum IGF-1 or IGFBP-3 levels after controlling for age, total energy, percent body fat, and education level. Total fat intake was significantly inversely correlated with serum IGFBP-3 level (r = -0.13, P = 0.04). The correlations of saturated and monounsaturated fats with serum IGFBP-3 were of borderline significance (r = -0.12, P = 0.06 and r = -0.11, P = 0.07, respectively).

Late onset of adrenocortical failure in GH deficiency with invisible pituitary stalk: a case report of a 48-year-old Japanese man and review of the literature

ACTH deficiency gradually develops in patients with growth hormone deficiency (GHD) who have abnormalities of the pituitary stalk on magnetic resonance imaging (MRI) following perinatal complications. We report here a rare case of GHD manifesting ACTH deficiency in middle age. A 48-year-old male patient was admitted to our hospital due to fever and hyponatremia. He was diagnosed as GHD and hypothyroidism at the age of 9, and had received lysine treatment until age 20, which was then replaced by thyroid hormone. He was not mentally retarded, but was the shortest in his class throughout his schooldays, reaching a final height of 148 cm. Hormonal examination revealed the presence of hypoadrenalism as indicated by poor responses of plasma cortisol to intravenous administration of corticotropin-releasing hormone (CRH) and insulin-induced hypoglycemia. Plasma ACTH responded well to CRH, but not to insulin-induced hypoglycemia, indicating that his hypoadrenalism was of hypothalamic origin. MRI showed an invisible pituitary stalk and relatively small pituitary gland. Since he had a perinatal abnormality, the damage around the pituitary and GHD could have originated from birth. In the literature, around 60% of GHD patients with pituitary stalk abnormalities develop hypoadrenalism due to ACTH deficiency, and more than 90% of such cases are diagnosed by age 30. We suggest that the appearance of hypoadrenalism should be carefully monitored in GHD patients with pituitary stalk abnormalities even after they reach middle age.

Effects of aging on hepatic IGF-I signaling

Little is known regarding hepatic insulin-like growth factor-1 IGF-I signaling with aging despite the observation that other tissues demonstrate resistance to IGF-I with aging and declines in liver mass accompany aging. Our aim was to determine if the IGF-I-induced signaling process changes with aging. Young (5 months) and old (24 months) C57BL/6 mice hepatic tissues and blood samples were taken 20 min after an intraperitoneal injection of desIGF-I. Age had no significant effect on plasma glucose, insulin and total IGF-I levels. IRS-1 protein was significantly decreased (33%) with aging. Basal phosphorylation of IRS-1, PKB and ERK were unaffected whereas basal phosphorylation of CREB and FKHR were significantly increased (37 and 33%, respectively) with aging. desIGF-I caused a significant decrease in plasma glucose concentrations in both young (53%) and old (44%) mice. desIGF-I administration significantly increased the phosphorylation of IRS-1 in both young (104%) and old (89%) hepatic tissues. Similarly, the phosphorylation of PKB was dramatically enhanced in both young (527%) and old (350%) hepatic tissues after desIGF-I stimulation. By contrast, desIGF-I administration had no significant effects on the phosphorylation of ERK and phosphorylation of transcription factors CREB and FKHR in both young and old hepatic tissues. These data suggest that aging dose not impair IGF-I signaling in hepatic tissues.

Bone metabolism and body composition in Japanese patients with active acromegaly

OBJECTIVE

Skeletal involvement is a common clinical feature in acromegalic patients. Although several recent reports are available concerning bone mineral density (BMD) in acromegaly, the controversy still exists as to whether BMD of acromegalic patients is increased or not. The present study was performed to examine biochemical bone metabolic indices and BMD as well as body composition in 26 Japanese patients with active acromegaly and 26 control subjects matched for age, sex, race and height in a cross-sectional study.

MEASUREMENTS

BMD of the lumbar spine and femoral neck, as well as body composition, was measured by dual-energy X-ray absorptiometry. Mid-radial BMD was measured by single-photon absorptiometry. We also determined serum levels of IGF-I, IGFBP-3 and osteocalcin (OC) as well as urinary levels of deoxy-pyridinoline (D-Pyr) and CrossLaps.

RESULTS

Percent lean body mass was increased and percent fat mass was decreased in the acromegalic patients compared to control subjects. Serum levels of OC, as well as urinary levels of D-Pyr and CrossLaps, were significantly higher in acromegalic patients compared to control subjects (9.8 +/- 1.2 vs. 5.7 +/- 0.77 for OC; 11.8 +/- 1.66 vs. 5.0 +/- 0.49 for D-Pyr; 437.6 +/- 68.4 vs. 156.5 +/- 39.6 for CrossLaps). Z scores of BMD at mid-radius as well as lumbar spine and femoral neck were significantly higher in acromegalic patients compared to control subjects (1.086 +/- 0.311 vs. -0.060 +/- 0.274 for mid-radius; 1.022 +/- 0.280 vs. 0.319 +/- 0.165 for lumbar spine; 1.292 +/- 0.347 vs. 0.232 +/- 0.264 for femoral neck).

CONCLUSIONS

The present study revealed that a decrease in percent fat mass and an increase in percent lean body mass were observed in Japanese patients with active acromegaly. Bone mineral density at all sites and bone metabolic markers were also increased in acromegaly. The present findings provide additional evidence that the GH/IGF-I axis might play an important role in the maintenance of bone mass as well as the regulation of body composition in Japanese adults.

Composição corpórea, distribuição de gordura e metabolismo de repouso em mulheres histerectomizadas no climatério: há diferenças de acordo com a forma da administração do estrogênio?

As mulheres no climatério sofrem inúmeras alterações metabólicas, cardiovasculares e de composição corporal. A terapêutica de reposição hormonal (TRH) vem alcançando importância na atualidade, tornando-se quase um consenso que a mulher após a menopausa deve receber hormônios, pelos benefícios que trazem para a saúde, tais como prevenção de doenças coronarianas e osteoporose. A forma de administração de estrogênios influi em uma série de parâmetros metabólicos; é sabido, por exemplo, que a administração oral provoca uma elevação no hormônio de crescimento (GH) e uma diminuição do IGFI: quanto à forma (transdérmica), os estudos ainda não são conclusivos quanto aos níveis do GH e IGFI. Por outro lado, o GH e o IGFI podem agir de maneiras diferentes no metabolismo lipídico, ósseo e na distribuição de gordura corpórea. O objetivo deste trabalho foi estudar as variações da distribuição visceral de gordura nas diferentes formas de administração estrogênica e, particularmente, verificar se a forma de administração do hormônio altera a quantidade de gordura visceral. Foram estudadas 33 mulheres no climatério, histerectomizadas, divididas em 3 grupos: 1) 13 pacientes recebendo estrogênio eqüino conjugado 0,625mg via oral diariamente; 2) 10 pacientes recebendo 17b estradiol TTS 50 2x/semana via transdérmica e; 3) 10 pacientes recebendo placebo. Estas pacientes foram submetidas: a) análise da composição corporal pelos métodos de bioimpedância (RJL 101-A) e densitometria óssea e corpórea (DEXA); b) análise da distribuição de gordura, particularmente de adiposidade visceral, pela tomografia computadorizada abdominal e; c) medida do metabolismo de repouso pelo calorímetro DELTA-TRAC. Foram ainda feitas dosagens laboratoriais de colesterol total e frações, triglicérides e glicemia aos 0,6 e 12 meses. Não observamos diferenças estatística significativas nos parâmetros estudados em nenhum dos 3 grupos (placebo, estrógeno oral e estrogênio transdérmico), embora notamos tendência a maior ganho de peso nos grupos com estrógenos e tendência a maior ganho de massa magra no grupo com estrogênio transdérmico.