麻豆传媒

AUSTIN -- Among patients with poorly controlled type 2 diabetes, researchers identified certain iron indices that were significantly associated with HbA1c levels.

The study, led by Rajeev Chawla, MD, of the North Delhi Diabetes Center and Maharaja Agrasen Hospital in New Delhi, found serum ferritin levels had a significantly positive correlation with HbA1c (r=0.43, P=0.001).

There also were significant positive correlations with microvascular complications, including nephropathy, retinopathy, and neuropathy resulting from type 2 diabetes, with elevated serum iron and serum ferritin levels (P=0.001), Chawla's group reported at the American Association of Clinical Endocrinologists (AACE) annual meeting.

"There isn't a lot of data," Chawla explained during an oral presentation, adding that in this study his research group aimed to further investigate the relationships between iron indices and A1c levels with potential complications.

He noted that in the event that elevated iron indices, such as serum iron and serum ferritin, may not be so high that they result in hemochromatosis, but these levels may still be high enough to be associated with adverse outcomes in type 2 diabetes.

The prospective, cross-sectional, single center study was conducted at the authors' hospital, and included 100 patients with type 2 diabetes who had A1c levels of greater than 7 at baseline (9.46 ± 1.31 mean HbA1c). These patients were compared with a control group that included 100 patients with type 2 diabetes and an HbA1c less than 7 (6.42 ± 0.28 mean HbA1c). The control group was also found to have a lower average duration of type 2 diabetes when compared to the study patients (5.26 versus 9.69 years).

After a collection of biomarker samples on serum iron levels, serum ferritin levels, and serum transferrin saturation, the researchers conducted a statistical analysis using SPSS software (version 17).

Across all biomarkers, Chawla's group reported higher average levels for the case group versus controls:

• Mean serum iron level: 155.08 μg/dl versus 88.81 μg/dl
• Serum ferritin: 284.79 ng/ml versus 181.31 ng/ml
• Serum transferrin saturation: 30.25 versus 28.92

However, the relationship between serum transferrin saturation and HbA1c levels was not found to be statistically significant (P=0.62), the authors reported.

Several microvascular complications were found to be associated with uncontrolled diabetes, when compared to controls in a secondary analysis. Specifically, nephropathy (Fisher-exact=20.374, P=0.001), retinopathy (Fisher-exact=14.103, P=0.001), and neuropathy (Fisher-exact=10.695, P=0.001) all had significant positive correlations with higher iron indices.

Using a scatter graph, Chawla's group also reported a correlation between duration of type 2 diabetes and HbA1c levels, with the presence of microvascular complications (P=0.001).

"Our study demonstrates that serum ferritin and serum iron level may be used as surrogate markers of poor glycemic control in type 2 diabetes, and it could be taken as a marker of microvascular risk also because there is a very strong positive correlation in serum ferritin and serum iron levels," Chawla stated.

However, Chawla cautioned that the findings should not be interpreted causally, and that the relationship between higher serum ferritin and iron levels with type 2 diabetes requires additional research. Current study limitations included a small sample size and limited cohort diversity.

"The results need to be corroborated with larger multiethnic and multicentric studies," he stated.

When an AACE attendee inquired about whether there was any longitudinal data after treatment, and how data may change after the case patients get HbA1c levels below 7, Chawla said his group is currently investigating this. He added that his group is following up with these patients for 2 years in order to assess the relationship between a reduction in HbA1c following treatment with subsequent changes in iron levels and microvascular complications.

Click for the American Association of Clinical Endocrinologists and American College of Endocrinology's 2017 comprehensive type 2 diabetes management algorithm.

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