LETTER TO THE EDITOR

Author reply to: serum ischaemic-modified albumin levels mightnot be a marker of oxidative stress in patientswith hypothyroidism

Inan Anaforoglu • Kerem Ersoy • Ekrem Algun

Received: 30 October 2013 / Accepted: 5 November 2013

� Springer Science+Business Media New York 2013

To the Editor,

We have read the critics of Reddy et al. [1] with a great

interest. We are grateful for the inspiring comments on our

manuscript reported in the April 2013 issue of the Endo-

crine [2].

The patients in our study were divided into three groups:

hypothyroid, subclinical hypothyroid and control. No sig-

nificant difference was determined among these three

groups in terms of the parameters hyperlipidemia and

metabolic syndrome. Hypothyroidism can give rise to

hypercholesterolemia, and this has been shown to be

reversible with thyroid hormone replacement [3]. The data

concerning the relation between subclinical hypothyroid-

ism and hyperlipidemia are inconsistent. There are studies

reporting no significant difference in plasma lipid levels in

patients with subclinical hypothyroidism compared to

controls [4, 5]. While in our study low-density lipoprotein

(LDL) cholesterol levels were slightly higher in patients

with evident hypothyroidism compared to those with sub-

clinical hypothyroidism and the control group, no statisti-

cally significant difference was determined. We already

have highlighted that as our groups did not differ for lipid

levels on contrary to Ma and colleaugues’ study [6] we

think that the possible effect that may arise from different

lipid levels have been excluded in our study. The relatively

low patient numbers in our study may have been involved

in this. While a relation is reported between total choles-

terol levels and ischaemic-modified albumin (IMA), this

was not evaluated in our study since it is not a component

of metabolic syndrome.

While metabolic syndrome was slightly higher in evi-

dently hypothyroid patients in our study, no statistically

significant difference was determined among the three

groups in terms of metabolic syndrome. There was no

significant difference between the metabolic patient and

control groups in terms of IMA levels. The authors pointed

the study by Gottlieb and colleagues in which IMA levels

were found to be higher than control group among patients

with metabolic syndrome; however, in that study also

similar to Ma and colleagues’ study [6] body mass index

(BMI), waist circumference, blood pressure (systolic and

diastolic), glucose levels and lipid levels (total cholesterol,

LDL and HDL) were higher among patients with metabolic

syndrome [7]. Although they have performed multivariate

analysis for BMI and lipids they do not ignore the potential

effect of these parameters on IMA levels in the discussion

section [7]. It has been reported that hypothyroidism and

subclinical hypothyroidism may be associated with an

atherosclerotic process and chronic ischaemia [8]. In

addition, a rise in metabolic rate as a result of the biological

effect of thyroid hormones and a rise in oxygen radicals

with calorigenesis has been reported [9]. It has also been

reported that metabolic processes decelerating in hypo-

thyroidism and decreasing oxygen radical production may

have a protective effect against ischaemia [10].

The authors emphasised that the level of albumin is

correlated with IMA levels and the absence of albumin

levels of our patients. They are completely right, but our

study group had no other diseases, other than thyroid dis-

ease; patients with abnormal albumin levels were not

included in the study. Testing the binding of albumin to

cobalt is a technique that measures IMA levels indirectly,

and low albumin levels have been reported to be capable of

affecting IMA levels. Gaze et al. reported a negative cor-

relation between serum albumin levels and IMA levels, but

I. Anaforoglu (&) � K. Ersoy � E. Algun

Department of Endocrinology and Metabolism, Trabzon Kanuni

Education and Research Hospital, 61000 Trabzon, Turkey

e-mail: ianaforoglu@hotmail.com

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Endocrine

DOI 10.1007/s12020-013-0116-7

emphasised that this was not very important between nor-

mal reference values. IMA levels must be carefully eval-

uated in hypoalbumenic patients [11]. As we mentioned, no

hypoalbuminemia was present. Serum albumin levels were,

therefore, not considered. The authors say that our study

results show that thyroid status has no influence on oxygen

radical production [1]. However, we did not make a com-

ment on oxygen radical production directly. As the authors

already had mentioned in their comments, there are many

indicators of oxygen radical production, IMA is just one of

these. We proposed that thyroid status has no effect on

IMA results. In our paper, we have emphasised that IMA

might not be a good marker for oxidative stress in patients

with thyroid disease, as well as the indirect relationship

between IMA and thyroid status.

In conclusion, our study determined no significant rise in

serum IMA levels in hypothyroid and subclinical hypo-

thyroid patients compared to the control group. Our study

involves a relatively small patient and control group and

can lead the way for more wide-ranging studies on the

subject.

References

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ischaemic-modified albumin levels might not be a marker of

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33(5), 325–331 (2013). doi:10.1007/s12020-013-0074-0

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