@article {1261, title = {A genome-wide association study identifies novel loci associated with circulating IGF-I and IGFBP-3.}, journal = {Hum Mol Genet}, volume = {20}, year = {2011}, month = {2011 Mar 15}, pages = {1241-51}, abstract = {

Insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) are involved in cell replication, proliferation, differentiation, protein synthesis, carbohydrate homeostasis and bone metabolism. Circulating IGF-I and IGFBP-3 concentrations predict anthropometric traits and risk of cancer and cardiovascular disease. In a genome-wide association study of 10 280 middle-aged and older men and women from four community-based cohort studies, we confirmed a known association of single nucleotide polymorphisms in the IGFBP3 gene region on chromosome 7p12.3 with IGFBP-3 concentrations using a significance threshold of P < 5 {\texttimes} 10(-8) (P = 3.3 {\texttimes} 10(-101)). Furthermore, the same IGFBP3 gene locus (e.g. rs11977526) that was associated with IGFBP-3 concentrations was also associated with the opposite direction of effect, with IGF-I concentration after adjustment for IGFBP-3 concentration (P = 1.9 {\texttimes} 10(-26)). A novel and independent locus on chromosome 7p12.3 (rs700752) had genome-wide significant associations with higher IGFBP-3 (P = 4.4 {\texttimes} 10(-21)) and higher IGF-I (P = 4.9 {\texttimes} 10(-9)) concentrations; when the two measurements were adjusted for one another, the IGF-I association was attenuated but the IGFBP-3 association was not. Two additional loci demonstrated genome-wide significant associations with IGFBP-3 concentration (rs1065656, chromosome 16p13.3, P = 1.2 {\texttimes} 10(-11), IGFALS, a confirmatory finding; and rs4234798, chromosome 4p16.1, P = 4.5 {\texttimes} 10(-10), SORCS2, a novel finding). Together, the four genome-wide significant loci explained 6.5\% of the population variation in IGFBP-3 concentration. Furthermore, we observed a borderline statistically significant association between IGF-I concentration and FOXO3 (rs2153960, chromosome 6q21, P = 5.1 {\texttimes} 10(-7)), a locus associated with longevity. These genetic loci deserve further investigation to elucidate the biological basis for the observed associations and clarify their possible role in IGF-mediated regulation of cell growth and metabolism.

}, keywords = {Aged, Chromosomes, Human, Pair 7, Cohort Studies, European Continental Ancestry Group, Female, Genome-Wide Association Study, Humans, Insulin-Like Growth Factor Binding Protein 3, Insulin-Like Growth Factor I, Male, Polymorphism, Single Nucleotide}, issn = {1460-2083}, doi = {10.1093/hmg/ddq560}, author = {Kaplan, Robert C and Petersen, Ann-Kristin and Chen, Ming-Huei and Teumer, Alexander and Glazer, Nicole L and D{\"o}ring, Angela and Lam, Carolyn S P and Friedrich, Nele and Newman, Anne and M{\"u}ller, Martina and Yang, Qiong and Homuth, Georg and Cappola, Anne and Klopp, Norman and Smith, Holly and Ernst, Florian and Psaty, Bruce M and Wichmann, H-Erich and Sawyer, Douglas B and Biffar, Reiner and Rotter, Jerome I and Gieger, Christian and Sullivan, Lisa S and V{\"o}lzke, Henry and Rice, Kenneth and Spyroglou, Ariadni and Kroemer, Heyo K and Ida Chen, Y-D and Manolopoulou, Jenny and Nauck, Matthias and Strickler, Howard D and Goodarzi, Mark O and Reincke, Martin and Pollak, Michael N and Bidlingmaier, Martin and Vasan, Ramachandran S and Wallaschofski, Henri} } @article {6189, title = {Sleep and insulin-like growth factors in the Cardiovascular Health Study.}, journal = {J Clin Sleep Med}, volume = {9}, year = {2013}, month = {2013 Dec 15}, pages = {1245-51}, abstract = {

STUDY OBJECTIVES: Sleep and sleep disordered breathing (obstructive sleep apnea [OSA]) are known to affect the growth hormone/insulin-like growth factor (GH/IGF) axis. There are few relevant population studies in this area, particularly in the elderly. We conducted this study to investigate the relationship between sleep (architecture and OSA) and circulating IGF-I (insulin-like growth factor-1), IGFBP-1 (insulin-like growth factor binding protein-1), and IGFBP-3 (insulin-like growth factor binding protein-3) levels in an elderly population.

DESIGN SETTING: Cross-sectional analysis of participants from the year 9 visit of the Cardiovascular Health Study (CHS) who were enrolled in the Sleep Heart Health Study (SHHS).

PATIENTS OR PARTICIPANTS: 1,233 elderly participants from the CHS and SHHS.

MEASUREMENTS AND RESULTS: The mean age of males (n = 526) and females (n = 697) was 77 years. The mean value of IGF-I (ng/mL) in males was 112.4 vs. 97.1 in females (p < 0.01). Mean IGFBP-1 and IGFBP-3 levels were higher in females than males (p < 0.01). As expected, slow wave sleep was better preserved in females compared to males (22\% total sleep time vs. 9\% total sleep time, p < 0.01). Furthermore, as expected, OSA (apneahypopnea index [AHI] >= 5/h) was more prevalent in males compared to females (60\% vs. 46\%, p < 0.01). Multivariable linear regression was used to determine the relationship between objective sleep parameters and circulating IGF-I, IGFBP-1, and IGFBP-3 levels, with adjustment for age, sex, race, BMI, diabetes, estrogen use, progestin use, and physical activity. We did not detect a significant association between slow wave sleep (SWS) (per 5 min) and IGF-I, IGFBP-1, and IGFBP-3 levels (ng/mL). We found no significant linear association between OSA (AHI >= 5/h) and IGF-I, IGFBP-1, and IGFBP-3 levels. Gender-stratification of the entire cohort did not alter these findings. Sensitivity analyses excluding diabetics revealed that moderate OSA (AHI >= 5 and < 15) is inversely associated with IGFBP-3 levels in women. Conclusions The relationship between SWS and GH/IGF system is not significant in the elderly. Furthermore, OSA does not appear to adversely influence the GH/IGF axis, as reported in younger individuals. Whether our study findings are due to diminished GH/IGF-I axis activity in elderly needs further investigation by replication in other large population based elderly cohorts.

}, keywords = {Aged, Cardiovascular Diseases, Cohort Studies, Cross-Sectional Studies, Female, Geriatric Assessment, Health Surveys, Humans, Insulin-Like Growth Factor Binding Protein 1, Insulin-Like Growth Factor Binding Protein 3, Insulin-Like Growth Factor I, Male, Sex Distribution, Sleep, Sleep Apnea, Obstructive, Somatomedins, United States}, issn = {1550-9397}, doi = {10.5664/jcsm.3260}, author = {Shah, Neomi and Rice, Tom and Tracy, Daniel and Rohan, Thomas and B{\r u}zkov{\'a}, Petra and Newman, Anne and Kaplan, Robert C} }