The impact of hypertension on leukocyte telomere length: a systematic review and meta-analysis of human studies

Abstract

Shortened leukocyte telomere length (LTL) is a novel biomarker for age and age-related diseases. Several epidemiological studies have examined the association between telomere length in surrogate tissues (for example, blood cells) and hypertension, and meanwhile the majority of studies reported an association some individual studies do not. We carried out a systematic review and meta-analysis to address the hypothesis that, in humans, telomere length is related with hypertension. Searches were conducted in Pubmed by September 2015 and reference lists of retrieved citations were hand searched. Eligible studies measured telomeres for both hypertensive and normotensive subjects. No restrictions were placed on sample size, publication type, age or gender. We calculated summary estimates using fixed and random effects meta-analysis. Publication bias and heterogeneity among studies were further tested. Meta-analyses from 3097 participants (1415 patients with hypertension and 1682 control subjects) showed a significant standardized mean difference between LTL in hypertensive patients and controls, either in the fixed (P<5 × 10) or the random model (P<0.005). Heterogeneity among studies was substantial (Q-statistic P-value <0.001, I 97.73%). Sensitivity analysis indicated that no single study changed the standardized mean difference qualitatively (0.022> random model P-value >0.002). Egger's test for asymmetry of effect sizes (intercept±s.e.=-7.278±3.574; P=0.072) did not show evidence for strong study publication bias. Leukocyte telomeres may be shorter in hypertensive than in normotensive individuals. Larger studies controlling for confounder effects are needed to confirm these findings and further explore sources of heterogeneity.

Association between leucocyte telomere length and cardiovascular disease in a large general population in the United States

“…Hypertension is a cardiovascular risk factor 42 , and our results also found an increase in the prevalence of CVD in hypertensive people (data not shown), which may affect the association. In addition, the LTL of non-hypertensive patients in the present study was longer than that of hypertensive patients, which was consistent with the results of a previous meta-analysis 43 , possibly due to the shortening of the telomere length of endothelial progenitor cells in hypertensive patients 44 . The presence of high blood pressure may have affected the association, but the specific reason is unknown.…”

Cigarette smoking and telomere length: A systematic review of 84 studies and meta-analysis

“…Another possible source of heterogeneity might be the inter-laboratory technical variation of quantitative PCR (qPCR) to measure relative telomere length, which tend to yield higher variability than Southern blotting ( Aviv et al, 2011 , Gardner et al, 2014 ), although a study by Martin-Ruiz et al suggested that both techniques show comparable intra- and inter-assay inconsistencies ( Martin-Ruiz et al, 2015 ). Previous meta-analyses on cross-sectional associations between other lifestyle-related factors such as hypertension or obesity and leukocyte telomere length also reported high heterogeneity ( Mundstock et al, 2015 , Tellechea and Pirola, 2016 ), which may indicate the need to address methodological problem in telomere association study that should involve standardisation of qPCR and Southern blotting protocols ( Martin-Ruiz et al, 2015 ).…”

Examining the gender difference in the association between metabolic syndrome and the mean leukocyte telomere length

“…Shorter telomere length, a cellular marker for biological age, was associated with a higher metabolic risk profiles, which remains unfavorable even after a period of 6 years[16]. Accumulating evidences demonstrated that shortened leukocyte telomere length had a significant association with stroke, myocardial infarction, and type 2 diabetes mellitus[17–19]. However, it is unclear whether gender differences existed in the association between MetS and leukocyte telomere length.…”