Circulating Stem Cells Associate With Adiposity and Future Metabolic Deterioration in Healthy Subjects.

Context: Obesity and metabolic syndrome are associated with mild leukocytosis, but whether hematopoietic stem/progenitor cells (HSPCs) play a role in metabolic deterioration is unknown.

Objective: Our objective was to analyze the cross-sectional and longitudinal associations between CD34(+) HSPCs, adiposity, and metabolic syndrome features.

Design: This is a cross-sectional study on 242 participants, 155 of whom were followed and included in a longitudinal assessment.

Setting: This study took place in a tertiary referral center for metabolic diseases.

Participants: Healthy working individuals attending a cardiovascular screening program (total n = 3158) and having a baseline measure of circulating CD34(+) cells participated.

Main Outcome Measures: We collected demographic and anthropometric data, cardiovascular risk factors, and metabolic syndrome parameters.

Results: Participants (34.7% males, mean age 45.9 ± 0.5 years) were free from diabetes and cardiovascular disease. Cross-sectionally, absolute CD34(+) cell counts were directly correlated with body mass index and waist circumference, inversely correlated with high-density lipoprotein cholesterol and the quantitative insulin sensitivity check index, and were higher in individuals with the metabolic syndrome. The hematopoietic component contributed most to the association of CD34(+) cells with adiposity. During a 6.3-year follow-up, high absolute levels of CD34(+) cells were associated with increasing waist circumference, declining quantitative insulin sensitivity check index and high-density lipoprotein cholesterol, and with incidence of metabolic syndrome. Relative CD34(+) cell counts showed weaker associations with metabolic parameters than absolute levels, but were longitudinally associated with increasing waist circumference and metabolic syndrome development.

Conclusions: A mild elevation of circulating CD34(+) progenitor cells, reflecting expansion of HSPCs, is associated with adiposity and future metabolic deterioration in healthy individuals.