Circulating insulin-like growth factor-binding protein 3 levels, independent of insulin-like growth factor 1, associate with truncal fat and systolic blood pressure in South Asian and white European preschool children

Association between insulin-like growth factor-1 and systolic blood pressure in children and adolescents with short stature

The relationship between insulin‐like growth factor‐1 (IGF‐1) and systolic blood pressure (SBP) is controversial in adults and children. The purpose of this study was to investigate the relationship between the IGF‐1 standard deviation score (IGF‐1 SDS) and SBP in children with short stature. A cross‐sectional analysis including 1315 children with short stature was conducted from March 2013 to October 2020. We estimated IGF‐1, blood pressure and other laboratory tests, and anthropometric indicators were also evaluated. Subgroup analyses of the pubertal stage, sex, growth hormone levels, thyroid hormone levels, fasting blood glucose levels, and triglyceride levels were performed. A positive association between the IGF‐1 SDS and SBP was observed by univariate analysis (p < .001). We further found a nonlinear association between the IGF‐1 SDS and SBP. The inflection point for the curve was found at an IGF‐1 SDS level of −2.91. In multivariate piecewise linear regression, there was a positive association between the IGF‐1 SDS and SBP when the IGF‐1 SDS was greater than −2.91 (β 1.56, 95% CI: 0.91, 2.22; p < .001). However, we did not observe a significant relationship between the IGF‐1 SDS and SBP when the IGF‐1 SDS level was less than −2.91 (β −0.95, 95% CI −3.17, 1.28; p = .379). This association was consistent across subgroup analyses. The present study demonstrated that there is a nonlinear relationship between the IGF‐1 SDS and SBP in children with short stature. Increased serum IGF‐1 levels were associated with elevated SBP when the IGF‐1 levels reached the inflection point.

Circulating IGF-1 Independently Predicts Blood Pressure in Children With Higher Calcium-Phosphorus Product Levels

OBJECTIVE

To study the association between insulin-like growth factor 1 (IGF-1) and blood pressure in children, in particular, the potential interaction with the serum calcium-phosphorus product (Ca*P).

METHODS

A longitudinal study included 521 children (age 8.8 ± 0.1) from northeastern Spain, of whom 158 were followed-up after 5 years. IGF-1, insulin-like growth factor-binding protein 3 (IGFBP-3), and serum calcium and phosphorus were measured at baseline. Anthropometric (body-mass index [BMI] and waist) and cardiometabolic variables (systolic [SBP] and diastolic blood pressure), pulse pressure, insulin, homeostatic model assessment of insulin resistance [HOMA-IR], high-density lipoprotein [HDL]-cholesterol, and triglycerides) were assessed at baseline and at the end of follow-up. Statistical analysis included Pearson correlations followed by multivariable linear regression analyses.

RESULTS

Baseline IGF-1 and IGF-1/IGFBP-3 molar ratio positively correlated with baseline and follow-up BMI, waist, SBP, pulse pressure, insulin, HOMA-IR and triglycerides (r 0.138-0.603; all P < 0.05). The associations with SBP were stronger with increasing Ca*P (r 0.261-0.625 for IGF-1; and r 0.174-0.583 for IGF-1/IGFBP-3). After adjusting for confounding variables, baseline IGF-1 and IGF-1/IGFBP-3 remained independently associated with both baseline and follow-up SBP in children in the highest Ca*P tertile (β = 0.245-0.381; P < 0.01; model R2 = 0.246-0.566).

CONCLUSIONS

Our results suggest that IGF-1 in childhood is an independent predictor of SBP in apparently healthy children, especially in those with high Ca*P levels.

Prenatal vitamin D and cord blood insulin-like growth factors in Dhaka, Bangladesh

Fetal growth restriction is linked to adverse health outcomes and is prevalent in low- and middle-income countries; however, determinants of fetal growth are still poorly understood. The objectives were to determine the effect of prenatal vitamin D supplementation on the insulin-like growth factor (IGF) axis at birth, to compare the concentrations of IGF-I in newborns in Bangladesh to a European reference population and to estimate the associations between IGF protein concentrations and birth size. In a randomized controlled trial in Dhaka, Bangladesh, pregnant women enrolled at 17-24 weeks of gestation were assigned to weekly oral vitamin D3 supplementation from enrolment to delivery at doses of 4200 IU/week, 16,800 IU/week, 28,000 IU/week or placebo. In this sub-study, 559 woman-infant pairs were included for analysis and cord blood IGF protein concentrations were quantified at birth. There were no significant effects of vitamin D supplementation on cord blood concentrations of IGF-I (P = 0.398), IGF-II (P = 0.525), binding proteins (BPs) IGFBP-1 (P = 0.170), IGFBP-3 (P = 0.203) or the molar ratio of IGF-I/IGFBP-3 (P = 0.941). In comparison to a European reference population, 6% of girls and 23% of boys had IGF-I concentrations below the 2.5th percentile of the reference population. IGF-I, IGF-II, IGFBP-3 and the IGF-I/IGFBP-3 ratio were positively associated with at least one anthropometric parameter, whereas IGFBP-1 was negatively associated with birth anthropometry. In conclusion, prenatal vitamin D supplementation does not alter or enhance fetal IGF pathways.

Sex differences in Alzheimer's disease: Understanding the molecular impact

Alzheimer's disease (AD) is a common neurodegenerative disorder that presents with cognitive impairment and behavioral disturbance. Approximately 5.5 million people in the United States live with AD, most of whom are over the age of 65 with two-thirds being woman. There have been major advancements over the last decade or so in the understanding of AD neuropathological changes and genetic involvement. However, studies of sex impact in AD have not been adequately integrated into the investigation of disease development and progression. It becomes indispensable to acknowledge in both basic science and clinical research studies the importance of understanding sex-specific differences in AD pathophysiology and pathogenesis, which could guide future effort in the discovery of novel targets for AD. Here, we review the latest and most relevant literature on this topic, highlighting the importance of understanding sex dimorphism from a molecular perspective and its association to clinical trial design and development in AD research field.

IGF-I and IGFBP-3 concentrations at 2 years: associations with anthropometry and milk consumption in an Indian cohort

BACKGROUND/OBJECTIVES

To ascertain associations between plasma insulin-like growth factor I (IGF-I), insulin-like growth factor-binding protein 3 (IGFBP-3) and their molar ratio at 2 y with neonatal size, infant growth, body composition at 2 y, and feeding practices in an Indian cohort.

SUBJECTS/METHODS

A cohort of 209 newborns, with 122 followed at 2 y. Anthropometry was conducted at birth and 2 y. IGF-I and IGFBP-3 concentrations were measured in cord blood and at 2 y. Maternal and child diet was assessed by food frequency questionnaires and maternal interviews. Multivariate regression was used to test for associations adjusting for confounding factors.

RESULTS

Mean 2 y plasma IGF-I and IGFBP-3 concentrations and IGF-I/IGFBP-3 were 49.4 ng/ml (95% CI: 44.1, 54.8), 1953.8 ng/ml (CI: 1870.6, 2036.9) ng/ml, and 0.088 (CI: 0.081, 0.095), respectively. IGF-I and IGF-I/IGFBP-3 were positively associated with current length, but not body mass index or adiposity. IGF-I was higher among those with greater change in length since birth. IGF-I concentrations were higher in children who drank the most milk (>500 vs. <250 ml per day: 65.6 vs. 42.8 ng/ml, p < 0.04), received other milk <6 months compared to ≥6 months (56.3 vs. 44.8 ng/ml, p < 0.05), and in those whose mothers consumed milk daily vs. less frequently in late pregnancy (56.4 vs. 42.7 ng/ml, p < 0.01). In multivariate regression, 2 y IGF-I concentration and IGF-I/IGFBP-3 were each positively associated with current length and milk intake. IGFBP-3 was not related to anthropometry or milk intake.

CONCLUSIONS

Plasma IGF-I concentrations and IGF-I/IGFBP-3 at 2 y are positively associated with length at 2 y and current milk intake.

MRI-determined total volumes of visceral and subcutaneous abdominal and trunk adipose tissue are differentially and sex-dependently associated with patterns of estimated usual nutrient intake in a northern German population

BACKGROUND

Visceral (VAT) and subcutaneous abdominal (SAAT) and trunk (STRAT) adipose tissue (AT) have been suggested to be differentially influenced by diet.

OBJECTIVE

We investigated whether and to what extent usual patterns of nutrient intake are associated with VAT, SAAT, and STRAT compared with nondietary predictors in northern German adults (n = 583).

DESIGN

AT volumes were quantified by magnetic resonance imaging. Nutrient intake was estimated by a 112-item food-frequency questionnaire linked to the German Food Code and Nutrient Database. Exploratory nutrient patterns were derived by principal components analysis (PCA) and partial least-squares regression (PLS) of 87 nutrients. Cross-sectional associations between nutrient patterns, single nutrients, or total energy intake and AT compartments were analyzed by multiple linear regression.

RESULTS

Next to sex and age, respectively, which were important nondietary predictors and accounted for more of the variation in VAT (∼13% and ∼4%) than in SAAT or STRAT (both 4-7% and <1%), variation in VAT (16.8% or 17.6%) was explained to a greater extent by 9 or 2 nutrient patterns derived by principal components analysis or partial least-squares regression, respectively, than was variation in SAAT (10.6% or 8.2%) or STRAT (11.5% or 8.6%). Whereas VAT (16.6%) was primarily explained by nutrient quality, SAAT (6.9%) and STRAT (7.4%) were mainly explained by total energy intake. VAT was positively associated with nutrients characteristic of animal (except for dairy) products, including arachidonic acid (standardized β: 0.25; 95% CI: 0.15, 0.34; P < 0.0001), but negatively with dietary fiber, including polypentoses (standardized β: -0.17; 95% CI: -0.24, -0.09; P < 0.0001), and nutrients found in milk. The direction and strength of many associations, however, depended strongly on sex and adjustment for BMI.

CONCLUSION

VAT may be particularly associated with sex-specific interplays of nutrients found in animal products and fiber, whereas SAAT and STRAT are associated with total energy intake.