RESEARCH ARTICLE
Open Access
Effects of phlebotomy-induced reduction of body
iron stores on metabolic syndrome: results from a
randomized clinical trial
Khosrow S Houschyar 1, Rainer Lüdtke 2 , Gustav J Dobos 1, Ulrich Kalus 3, Martina Broecker-Preuss 4, Thomas Rampp 1, Benno Brinkhaus 5 and Andreas Michalsen 5,6
Abstract
Background:
Metabolic syndrome (METS) is an increasingly prevalent but poorly understood clinical condition
characterized by insulin resistance, glucose intolerance, dyslipidemia, hypertension, and obesity. Increased oxidative
stress catalyzed by accumulation of iron in excess of physiologic requirements has been implicated in the
pathogenesis of METS, but the relationships between cause and effect remain uncertain. We tested the hypothesis
that phlebotomy-induced reduction of body iron stores would alter the clinical presentation of METS, using a
randomized trial.
Methods:
In a randomized, controlled, single-blind clinical trial, 64 patients with METS were randomly assigned to
iron reduction by phlebotomy (n = 33) or to a control group (n = 31), which was offered phlebotomy at the end
of the study (waiting-list design). The iron-reduction patients had 300 ml of blood removed at entry and between
250 and 500 ml removed after 4 weeks, depending on ferritin levels at study entry. Primary outcomes were change
in systolic blood pressure (SBP) and insulin sensitivity as measured by Homeostatic Model Assessment (HOMA)
index after 6 weeks. Secondary outcomes included HbA1c, plasma glucose, blood lipids, and heart rate (HR).
Results:
SBP decreased from 148.5 ± 12.3 mmHg to 130.5 ± 11.8 mmHg in the phlebotomy group, and from 144.7 ±
14.4 mmHg to 143.8 ± 11.9 mmHg in the control group (difference -16.6 mmHg; 95% CI -20.7 to -12.5;
P < 0.001). No significant effect on HOMA index was seen. With regard to secondary outcomes, blood glucose, HbA1c, low-density lipoprotein/high-density lipoprotein ratio, and HR were significantly decreased by phlebotomy. Changes in BP and HOMA index correlated with ferritin reduction.
Conclusions:
In patients with METS, phlebotomy, with consecutive reduction of body iron stores, lowered BP and
resulted in improvements in markers of cardiovascular risk and glycemic control. Blood donation may have
beneficial effects for blood donors with METS.
Trial registration:
ClinicalTrials.gov: NCT01328210
Please see related article: http://www.biomedcentral.com/1741-7015/10/53
Open Access
Effects of phlebotomy-induced reduction of body
iron stores on metabolic syndrome: results from a
randomized clinical trial
Khosrow S Houschyar 1, Rainer Lüdtke 2 , Gustav J Dobos 1, Ulrich Kalus 3, Martina Broecker-Preuss 4, Thomas Rampp 1, Benno Brinkhaus 5 and Andreas Michalsen 5,6
Abstract
Background:
Metabolic syndrome (METS) is an increasingly prevalent but poorly understood clinical condition
characterized by insulin resistance, glucose intolerance, dyslipidemia, hypertension, and obesity. Increased oxidative
stress catalyzed by accumulation of iron in excess of physiologic requirements has been implicated in the
pathogenesis of METS, but the relationships between cause and effect remain uncertain. We tested the hypothesis
that phlebotomy-induced reduction of body iron stores would alter the clinical presentation of METS, using a
randomized trial.
Methods:
In a randomized, controlled, single-blind clinical trial, 64 patients with METS were randomly assigned to
iron reduction by phlebotomy (n = 33) or to a control group (n = 31), which was offered phlebotomy at the end
of the study (waiting-list design). The iron-reduction patients had 300 ml of blood removed at entry and between
250 and 500 ml removed after 4 weeks, depending on ferritin levels at study entry. Primary outcomes were change
in systolic blood pressure (SBP) and insulin sensitivity as measured by Homeostatic Model Assessment (HOMA)
index after 6 weeks. Secondary outcomes included HbA1c, plasma glucose, blood lipids, and heart rate (HR).
Results:
SBP decreased from 148.5 ± 12.3 mmHg to 130.5 ± 11.8 mmHg in the phlebotomy group, and from 144.7 ±
14.4 mmHg to 143.8 ± 11.9 mmHg in the control group (difference -16.6 mmHg; 95% CI -20.7 to -12.5;
P < 0.001). No significant effect on HOMA index was seen. With regard to secondary outcomes, blood glucose, HbA1c, low-density lipoprotein/high-density lipoprotein ratio, and HR were significantly decreased by phlebotomy. Changes in BP and HOMA index correlated with ferritin reduction.
Conclusions:
In patients with METS, phlebotomy, with consecutive reduction of body iron stores, lowered BP and
resulted in improvements in markers of cardiovascular risk and glycemic control. Blood donation may have
beneficial effects for blood donors with METS.
Trial registration:
ClinicalTrials.gov: NCT01328210
Please see related article: http://www.biomedcentral.com/1741-7015/10/53
