Height indicates hematopoietic capacity in elderly Japanese men

Abstract

Previously, we reported that height is an indicator of the capacity of vascular repair in elderly men, especially hypertensive men. On the other hand, hemoglobin could act as a possible biochemical index of hypertension-induced vascular damage. However, no studies have clarified the correlation between height and hematopoietic activity. We conducted a cross-sectional study of 249 men aged 65-69 undergoing a general health check-up. Reticulocyte was used to evaluate hematopoietic activity. Because hemoglobin concentration should influence hematopoietic activity, analyses stratified by hemoglobin level were performed. Independent of known cardiovascular risk factors and other hematological parameters (white blood cell count), a significant positive correlation was seen between height and reticulocytes for total subjects and subjects with a high hemoglobin concentration (≥14.5 g/dL), but not in subjects with a low hemoglobin concentration (<14.5 g/dL). The standardized parameter estimates (β) were β=0.18, p=0.003 for total subjects, β=0.28, p=0.001 for subjects with a high hemoglobin concentration, and β=0.03, p=0.717 for subjects with low hemoglobin. Independently, height is significantly positively correlated with reticulocyte in elderly Japanese men, particularly in men with a high hemoglobin concentration. These results indicate that subjects with a short stature might have lower hematopoietic capacity than those with a high stature.

Possible mechanism underlying the association between height and vascular remodeling in elderly Japanese men

“…Further investigations with a larger number of subjects with high hemoglobin and circulating CD34-positive cell data that enables us to perform circulating CD34-positive cell level-specific analysis will be necessary. In addition to these mechanisms, in our present study, we found a significant positive association between height and reticulocytes among subjects with a high hemoglobin concentration, as shown in a previous study [ 27 ]. Since endothelial activity is strongly associated with bone marrow activity [ 13 , 23 ] and reticulocytes act as an indicator of such activity, this positive association between height and reticulocytes may also partly indicate that subjects with a short stature might be at a disadvantage as a result of deficient endothelial repair.…”

“…Since short stature is associated with inflammatory disadvantages [ 5 , 6 ], this type of ceiling effect should act as a strong confounding factor on the association between height and platelet count. We also previously reported that height is positively associated with hematopoietic capacity [ 27 ], and bone marrow stroma cells differentiate into megakaryocytes that subsequently produce platelets [ 29 ]. In the present study population, reticulocytes were found to be significantly positively associated with height.…”

“…Potential limitations of this study warrant consideration. Because creatinine clearance data were not available and estimated glomerular filtration rate (GFR) is not an effective tool for evaluating kidney function for a comparison of associations with various body heights [ 1 , 2 , 5 , 27 , 28 , 32 ], we were not able to perform an analysis adjusted for exact renal function. However, our study showed that the association between height and platelet count remained significant even after adjustment for serum creatinine.…”

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“…Further investigations with a larger number of subjects with high hemoglobin and circulating CD34-positive cell data that enables us to perform circulating CD34-positive cell level-specific analysis will be necessary. In addition to these mechanisms, in our present study, we found a significant positive association between height and reticulocytes among subjects with a high hemoglobin concentration, as shown in a previous study [27]. Since endothelial activity is strongly associated with bone marrow activity [13,23] and reticulocytes act as an indicator of such activity, this positive association between height and reticulocytes may also partly indicate that subjects with a short stature might be at a disadvantage as a result of deficient endothelial repair.…”

“…Because creatinine clearance data were not available and estimated glomerular filtration rate (GFR) is not an effective tool for evaluating kidney function for a comparison of associations with various body heights [1,2,5,27,28, 32], we were not able to perform an analysis adjusted for exact renal function. However, our study showed that the association between height and platelet count remained significant even after adjustment for serum creatinine.…”