Association between IGF-1 levels ranges and all-cause mortality: A meta-analysis

The association between IGF-1 levels and mortality in humans is complex with low levels being associated with both low and high mortality. The present meta-analysis investigates this complex relationship between IGF-1 and all-cause mortality in prospective cohort studies. A systematic literature search was conducted in PubMed/MEDLINE, Scopus, and Cochrane Library up to September 2019. Published studies were eligible for the meta-analysis if they had a prospective cohort design, a hazard ratio (HR) and 95% confidence interval (CI) for two or more categories of IGF-1 and were conducted among adults. A random-effects model with a restricted maximum likelihood heterogeneity variance estimator was used to find combined HRs for all-cause mortality. Nineteen studies involving 30,876 participants were included. Meta-analysis of the 19 eligible studies showed that with respect to the low IGF-1 category, higher IGF-1 was not associated with increased risk of all-cause mortality (HR = 0.84, 95% CI = 0.68–1.05). Dose–response analysis revealed a U-shaped relation between IGF-1 and mortality HR. Pooled results comparing low vs. middle IGF-1 showed a significant increase of all-cause mortality (HR = 1.33, 95% CI = 1.14–1.57), as well as comparing high vs. middle IGF-1 categories (HR = 1.23, 95% CI = 1.06–1.44). Finally, we provide data on the association between IGF-1 levels and the intake of proteins, carbohydrates, certain vitamins/minerals, and specific foods. Both high and low levels of IGF-1 increase mortality risk, with a specific 120–160 ng/ml range being associated with the lowest mortality. These findings can explain the apparent controversy related to the association between IGF-1 levels and mortality

Thresholds of handgrip strength for all-cause, cancer, and cardiovascular mortality: A systematic review with dose-response meta-analysis

Background While handgrip strength is associated with all-cause and cause-specific mortality, whether such associations are dose-dependent is largely unknown. Therefore, we conducted a systematic review on the dose-response relationship of handgrip strength with all-cause mortality, cancer, and cardiovascular mortality. Methods The data source included three electronic databases (PubMed/MEDLINE, Web of Science and Scopus) from inception to 8 February 2022. Prospective cohort studies of healthy adults with objective measures of handgrip strength were included. Two researchers independently screened studies, extracted data, and assessed risk of bias. We used estimates regarding handgrip strength categories to conduct a random forest model, and a two-stage random-effects hierarchical meta-regression model pooling study-specific estimates for dose-response relationship. Outcomes included all-cause, cancer, and cardiovascular mortality. Reults Forty-eight studies comprising 3,135,473 participants (49.6% women, age range 35–85 years) were included. Random forest models showed a significant inverse association between handgrip strength and all-cause and cause-specific mortality. Dose-response meta-analyses showed that higher levels of handgrip strength significantly reduced the risk of all-cause mortality within 26–50 kg (Higgin´s I2 =45.7%) in a close-to-linear inverse fashion. Cancer and cardiovascular mortality displayed a trend towards a U-shaped association with a significant risk reduction between 16 and 33 kg (Higgin´s I2 =77.4%), and a close-to-linear inverse shaped and significant risk reduction ranging from 24 to 40 kg (Higgin´s I2 =79.7%) respectively. Conclusion There is strong evidence for an association between lower handgrip strength with higher all-cause, cancer, and cardiovascular mortality risk. The dose-response relationship of handgrip strength substantially varies depending on the cause of mortality

Association between IGF-1 levels ranges and all-cause mortality: A meta-analysis

The association between IGF-1 levels and mortality in humans is complex with low levels being associated with both low and high mortality. The present meta-analysis investigates this complex relationship between IGF-1 and all-cause mortality in prospective cohort studies. A systematic literature search was conducted in PubMed/MEDLINE, Scopus, and Cochrane Library up to September 2019. Published studies were eligible for the meta-analysis if they had a prospective cohort design, a hazard ratio (HR) and 95% confidence interval (CI) for two or more categories of IGF-1 and were conducted among adults. A random-effects model with a restricted maximum likelihood heterogeneity variance estimator was used to find combined HRs for all-cause mortality. Nineteen studies involving 30,876 participants were included. Meta-analysis of the 19 eligible studies showed that with respect to the low IGF-1 category, higher IGF-1 was not associated with increased risk of all-cause mortality (HR = 0.84, 95% CI = 0.68–1.05). Dose–response analysis revealed a U-shaped relation between IGF-1 and mortality HR. Pooled results comparing low vs. middle IGF-1 showed a significant increase of all-cause mortality (HR = 1.33, 95% CI = 1.14–1.57), as well as comparing high vs. middle IGF-1 categories (HR = 1.23, 95% CI = 1.06–1.44). Finally, we provide data on the association between IGF-1 levels and the intake of proteins, carbohydrates, certain vitamins/minerals, and specific foods. Both high and low levels of IGF-1 increase mortality risk, with a specific 120–160 ng/ml range being associated with the lowest mortality. These findings can explain the apparent controversy related to the association between IGF-1 levels and mortality.Funding was provided by the USC Edna Jones chair fund and NIH P01 AG055369?01 to V.D.L.Scopu