Serum Insulin‐Like Growth Factor I in Healthy Older Men in Relation to Physical Activity

Rudman, Daniel; Mattson, Dale E.

doi:10.1111/j.1532-5415.1994.tb06076.x

Cited by 47 publications

(15 citation statements)

References 31 publications

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“…The relationship of physical activity and IGF levels has been similarly inconsistent. Most studies, like our own, found no association [14,22,28,44,50], although others observed inverse [35] or positive [25,51] associations. The relationship between physical activity and IGF levels is complex.…”

Section: Anthropometry and Physical Activitymentioning

confidence: 78%

“…These included demographics (age, sex, and race) [22-27, 30, 33, 41], anthropometrics (height, BMI) [14,22,23,25,26,28,[30][31][32][42][43][44][45][46][47][48][49], recent vigorous physical activity [14,22,25,28,35,44,50,51], smoking [22, 25-28, 30, 32, 47], reproductive factors [25][26][27][28], and milk consumption [38,52,53], as well as some that have not specifically been evaluated (aspirin/NSAIDs use, multivitamin and calcium supplement use). Data were analyzed using multivariate linear regression to evaluate the association between lifestyle (independent variables) and circulating IGF-1, IGFBP-3, and their molar ratio (dependent variables).…”

Section: Analysesmentioning

confidence: 99%

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Variation in Plasma Insulin-like Growth Factor-1 and Insulin-like Growth Factor Binding Protein-3: Personal and Lifestyle Factors (United States)

Morimoto

Newcomb

White

et al. 2005

Cancer Causes Control

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Insulin-like growth factors (IGFs) play an important role in cell proliferation and apoptosis, and recent epidemiologic studies have suggested that circulating IGF-1 and IGF binding protein-3 (IGFBP-3) may be related to colorectal, breast, and prostate cancer risk. The purpose of this analysis was to investigate the role of various personal and lifestyle factors in the inter-individual variation of circulating IGF-1 and IGFPB-3. We measured plasma levels of IGF-1 and IGFBP-3 in a sequential sample of 333 population-based control subjects enrolled in the Seattle Colorectal Cancer Family Registry from August 1999 through December 2001, who had provided a blood sample. Total IGF-1 and IGFBP-3 were measured from plasma samples using ELISA assays. Interviewer-administered questionnaires collected data on various personal and lifestyle factors. Multivariate-adjusted linear regression was used to assess the associations between specific personal and lifestyle factors with IGF-1 and IGFBP-3 levels. Age, body mass index, and postmenopausal hormone use were statistically significantly inversely related to IGF-1 concentrations, and milk consumption was significantly positively related to IGF-1 levels. Only age was significantly related to circulating IGFBP-3. Although the sources of inter-individual variation of IGF-1 and IGFB-3 are not yet fully understood, this analysis provides some insights into factors that may contribute.

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Section: Anthropometry and Physical Activitymentioning

confidence: 78%

Section: Analysesmentioning

confidence: 99%

Variation in Plasma Insulin-like Growth Factor-1 and Insulin-like Growth Factor Binding Protein-3: Personal and Lifestyle Factors (United States)

Morimoto

Newcomb

White

et al. 2005

Cancer Causes Control

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“…Furthermore, although there are no data available on a possibly age-dependent decline in paracrine secretion of IGF-1, it is a matter of fact that the humoral concentration of IGF-1 is drastically decreased by aging [31] . Therefore it could be that the role of IGF-1 is progressively assumed by insulin as age advances as its secretion progressively increases in adult age [32] .…”

Section: Discussionmentioning

confidence: 99%

On How Insulin May Influence Ageing and Become Atherogenic throughout the Insulin-Like Growth Factor-1 Receptor Pathway: In vitro Studies with Human Vascular Smooth Muscle Cells

Ruíz-Torres

Lozano

Melón³

et al. 2005

Gerontology

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Background: It is known that growth factors play a role in ageing and atherogenesis, and insulin develops mitogenic activity in vitro. Objectives: This study focusses on the pathway by which insulin induces proliferation and mobility in vascular smooth muscle cells (SMCs) compared with that of insulin-like growth factor-1 (IGF-1), because they are two basic phenomena for atherogenesis that could also help to understand the role of insulin in the ageing process. Methods: Bromodeoxyuridine DNA incorporation, chemotaxis and the appearance of membrane ruffles were measured in cultured SMCs after incubation with insulin or IGF-1 in the presence of insulin or IGF-1 receptor-blocking antibodies. Results: Insulin-induced SMC proliferation through the IGF-1 receptors; indeed, the blockade of insulin receptors does not inhibit the mitogenic influence of insulin. On the contrary, insulin-induced cell migration was inhibited by blocking the insulin receptor but not the IGF-1 receptor. Nevertheless, in less differentiated SMCs from non-confluent cultures, the migratory response was significantly higher and insulin lost its receptor specificity. It was stimulated through receptors both for insulin and IGF-1. In these cases the IGF-1 action was similar. Insulin-induced F-actin rearrangements took place through both types of receptors, but IGF-1 was a little more specific through its own receptors. Conclusion: The pathway activated by insulin to induce SMC proliferation is not different from that of IGF-1, whereas the unspecific mechanism inducing mobility in growing cells seems to be related to a higher sensitivity response. Cells with the highest mitotic activity have the highest mobility in which stimulation of receptor specificity is lost for either insulin or IGF-1. Extrapolating these results to in vivo, insulin could become relevant for inducing stabilization and also side effects in ageing.

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“…A negative correlation between tIGF-I and fitness was later suggested in a study where physically active elderly were compared with sedentary elderly, but fitness and energy expenditure were not assessed [56]. More recently, Eliakim et al have demonstrated a positive correlation between tIGF-I and VO 2 max in pre-pubertal girls [57], while this apparent relationship did not reach significance in adolescent girls [58].…”

Section: Effects Of Training On Tigf-i Concentrationsmentioning

confidence: 99%

Exercise and Circulating Insulin-Like Growth Factor I

Berg

Bang²

2004

Horm Res Paediatr

103

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Determinations of serum concentrations of total insulin-like growth factor I (tIGF-I) are important in the diagnosis, monitoring of treatment and safety evaluation of patients with growth disorders and/or metabolic disease. It is well established that tIGF-I status varies over time. Changes in tIGF-I levels in relation to an acute bout of exercise or repeated bouts, known as training, are likely to contribute to this variation. Serum tIGF-I has also been found to be of predictive value in growth prediction models employed before the start of growth hormone (GH) treatment. Furthermore, IGF-I generation tests have been suggested to be of value in the assessment of the growth response to GH administration in patients suspected of GH deficiency with or without some degree of GH insensitivity. This is discussed elsewhere in this issue. Recent progress in our understanding of growth hormone-dependent and -independent expression of the IGF1 gene in skeletal muscle and the role of sufficient energy intake during training for muscle and liver generation of IGF-I raises important questions regarding their relative contribution to the circulating pool of IGF-I. The present review is focused on circulating levels of tIGF-I in relation to a single bout of exercise or to a period of training. In addition, the expression of IGF-I locally in muscle in response to these stimuli will be discussed.

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Serum Insulin‐Like Growth Factor I in Healthy Older Men in Relation to Physical Activity

Abstract: The data do not support the hypothesis that lack of physical activity is responsible for the decline in serum IGF-I with advancing age.

Cited by 47 publications

References 31 publications

Variation in Plasma Insulin-like Growth Factor-1 and Insulin-like Growth Factor Binding Protein-3: Personal and Lifestyle Factors (United States)

Variation in Plasma Insulin-like Growth Factor-1 and Insulin-like Growth Factor Binding Protein-3: Personal and Lifestyle Factors (United States)

On How Insulin May Influence Ageing and Become Atherogenic throughout the Insulin-Like Growth Factor-1 Receptor Pathway: In vitro Studies with Human Vascular Smooth Muscle Cells

Exercise and Circulating Insulin-Like Growth Factor I

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