Telomere Length Is Not Related to Established Cardiovascular Risk Factors but Does Correlate with Red and White Blood Cell Counts in a German Blood Donor Population

Abstract

Telomere length (TL) is considered a marker of biological aging and has been associated with the presence of various coronary risk factors in patients. Much less is known about the relationships between TL and classic coronary risk factors in other populations. We measured TL in peripheral blood leukocytes of 343 middle-aged blood donors (mean age 40.2 ± 12.4 years; 201 men, 142 women) using quantitative polymerase chain reaction. Median TL was 0.86 (range: 0.48–1.85) relative TL units. In linear regression analyses with natural log-transformed T to S ratio as the dependent variable, there was a significant association with age (per year: beta = -0.007, p<0.001) and sex (males vs. females: beta = 0.075, p = 0.007) with longer telomeres in men. After adjusting for these two variables, we observed no association of TL with classic coronary risk factors including cholesterol (p = 0.36), triglyceride (p = 0.09), HDL-cholesterol (p = 0.26), LDL-cholesterol (p = 0.36), smoking (p = 0.97), and personal (p = 0.46) or family history (p = 0.63) of cardiovascular disease. However, we did find a significant positive association with white (p = 0.011) and red blood cell count (p = 0.031), hemoglobin (p = 0.014) and hematocrit (p = 0.013); we also found a borderline positive association with thrombocytes (p = 0.074). Positive associations remained significant for hemoglobin (p = 0.017), hematocrit (p = 0.023), and leukocytes (p = 0.009) in a subgroup with no reported vascular disease; associations were of borderline significance for erythrocytes (p = 0.053) and thrombocytes (p = 0.088) in this subgroup. The data do not support the concept that classic coronary risk factors contribute to telomere attrition in a blood donor population. However, telomere attrition may be a marker for reduced proliferation reserve in hematopoietic progenitor cells.

Less Than Ideal Cardiovascular Health Is Associated With Shorter Leukocyte Telomere Length: The National Health and Nutrition Examination Surveys, 1999–2002

“…[12][13][14][15][16][17] However, others have failed to replicate these findings. [18][19][20][21] For example, a study by Menke et al found no association between LTL and type 2 diabetes mellitus using the same NHANES data. 19 The reasons for these inconsistencies are not completely understood, but it is likely that LTL shortening is the result of the overall impact of multiple CVD risk factors working in tandem than a single CVD risk factor.…”

“…Some studies have reported a significant association of shorter LTL with cigarette smoking, obesity, physical inactivity, poor diet, hypertension, and type 2 diabetes mellitus . However, others have failed to replicate these findings . For example, a study by Menke et al found no association between LTL and type 2 diabetes mellitus using the same NHANES data .…”

“…[12][13][14][15][16][17] However, other studies did not find such an association between LTL and individual CVD risk factors. [18][19][20][21] For example, a recent study found no association between LTL and type 2 diabetes mellitus in a large, nationally representative sample of US adults. 19 The reasons for these inconsistencies remain the subject of further research, but it has been attributed to differences in populations, methods used to measure telomere length, poor measurements of telomere length, small and nonrepresentative samples, or failure to account for potential confounders.…”

Telomere Shortening, Regenerative Capacity, and Cardiovascular Outcomes

“…We did not observe any statistically significant association between LTL and other leukocyte counts, suggesting that shorter LTL is a reflection of bone marrow regenerative capacity rather than global circulating cellular reserve, although this issue remains controversial. 42–48 …”

Interactions between UCP2 SNPs and telomere length exist in the absence of diabetes or pre-diabetes

“…Within the current study, we also find shorter LTL is associated with a higher level of triglycerides (coefficient = −0.016, P = 0.041). Previous studies have demonstrated a mixed relationship between high triglyceride levels and shorter telomeres, with some studies demonstrating a significant relationship 41 42 , whereas other studies have not 43 44 . Interestingly, in a study of subjects with diabetes, the presence of the GG genotype of the -866G/A (rs659366) is associated with higher triglycerides (≥1.70 mM), total cholesterol (≥6.0 mM) and LDL-cholesterol (≥3.35 mM) levels in T2DM patients 45 .…”