Evaluation of thyroid function in type 2 diabetes in north-eastern part of India: A hospital-based study

Prevalence and Association of Thyroid Dysfunction With Diabetes Mellitus in a Tertiary Care Hospital: A Retrospective Study

BACKGROUND

Thyroid dysfunction and diabetes mellitus are endocrine disorders that are closely associated with insulin resistance. Thyroid dysfunction has been found to be more common in patients with diabetes compared to those without. In India, thyroid dysfunction is common among patients with diabetes, with a high prevalence found in Tamil Nadu, where subclinical hypothyroidism also contributes significantly.

AIM

This study aims to determine the prevalence and association of thyroid dysfunction among patients with type 2 diabetes mellitus.

METHODOLOGY

A retrospective cross-sectional study was conducted from August 2023 to August 2024. A total of 91 patients with diabetes were screened for thyroid dysfunction. Data on demographics, comorbidities, duration of diabetes, glycated hemoglobin (HbA1c), and thyroid function (triiodothyronine, thyroxine, and thyroid-stimulating hormone) were collected. Statistical analysis was performed to identify the association among thyroid dysfunction, glycemic control, and diabetes mellitus duration.

RESULTS

Thyroid dysfunction was identified in 21 (23.1%) of the study population, with 19 (20.9%) patients experiencing hypothyroidism and two (2.2%) patients experiencing hyperthyroidism. The prevalence was found to be high in women. Subjects with diabetes for more than five years had a high prevalence of thyroid dysfunction. HbA1c did not show any significant correlation (p = 0.327).

CONCLUSION

This study shows the prevalence of thyroid dysfunction, especially hypothyroidism, among patients with diabetes. It also highlights the importance of screening for thyroid function in patients who have had diabetes for more than five years. Early identification and management of thyroid dysfunction may improve glycemic control and reduce the risk of long-term complications.

Spectrum of thyroid function test among type 2 diabetic patients attending a rural health facility, southwest Nigeria: A hospital-based study

Objectives:

The thyroid gland produces hormones that have significant influence on carbohydrate metabolism; its disorders may affect carbohydrate metabolism in type 2 diabetic patients (T2DM) more than the non-diabetic (NDM) patients as reported in various studies. We determined the spectrum of thyroid function tests (TFTs) profile among T2DM in our rural health facility.

Methods:

T2DM patients and NDM patients were recruited for the study. The age, educational level, occupation, marital status, and duration of diabetes were extracted from interviewer’s administered questionnaire. The weight, height, body mass indices (BMIs), and the waist and hip circumferences were measured. Waist-hip ratios (WHR) were calculated for all participants. Venous blood was collected and assayed for free triiodothyronine (fT3), free thyroxine (fT4), and thyroid stimulating hormone (TSH) using a Chemiluminescence Immunoassay (CLIA) 2nd Generation Autoanalyzer. The mean, standard deviation, frequencies, and percentages were calculated for the variables. The student’s t-test and chi-square test were also determined as appropriate.

Results:

Seventy-eight patients made up of 56 T2DM and 22 NDM were evaluated in this study. Fifty-one were males while 27 were females; 67.9% and 59.1% of the female participants were T2DM and NDM, respectively. The WHR was significantly higher in T2DM than NDM (0.92 ± 0.05 versus 0.88 ± 0.06). The TSH was higher in T2DM than the NDM. Forty-four (78.6%) of the T2DM had euthyroid (normal) biochemical pattern; 12 (21.4%) showed abnormal biochemical pattern of euthyroid sick syndrome, subclinical hyperthyroid, and subclinical hypothyroid. Thirty (53.6%) of the T2DM were diagnosed less than five years ago. The value of TSH was increasing with the duration of diabetes but not in a statistically significant way. None of the T2DM showed overt hypothyroid or hyperthyroid test result.

Conclusion:

Thyroid function test may identify diabetics with altered thyroid hormone status that may impact on their metabolic control. Knowledge of the functional state of the thyroid gland can help in achieving a better metabolic control and attenuate the development of complications in T2DM.

Autoimmune Thyroid Disease is Associated with a Lower Prevalence of Diabetic Retinopathy in Patients with Type 1 Diabetic Mellitus

Background and objectives: The aim of the study was to assess the correlation of autoimmune thyroid diseases (AITD) in patients with diabetes mellitus type 1 (DM1) with the occurrence of diabetic retinopathy (DR). Materials and Methods: The inclusion criteria for the study were: type 1 diabetes diagnosed on the basis of WHO criteria lasting at least a year, presence of AITD for at least a year, and age over 18 years. The control group consisted of patients without diagnosed AITD (DM1noAITD), selected according to age, BMI and DM1 duration. Anthropometric parameters, metabolic risk factors such as glycated hemoglobin (HbA1c), lipids and blood pressure, thyroid status and the presence of DR were assessed. Results: The study involved 200 patients with type 1 diabetes aged 36 ± 12 years, 70 men and 130 women. Patients from the study group (DM1AITD) had significantly lower creatinine concentration, significantly lower systolic blood pressure (SBP), glycated hemoglobin (HbA1c) percentage and triglyceride (TG) concentration, and higher high-density lipoprotein (HDL-cholesterol) concentration than the control group (DM1noAITD). There was a significantly lower chance of non-proliferative diabetic retinopathy (NPDR) among DM1AITD than in the control group. Conclusions: Patients with DM1 and AITD were metabolically better balanced, as evidenced by a significantly lower SBP, percentage of HbA1c and TG, as well as significantly higher HDL-cholesterol in this group. Patients with DM1 and AITD were significantly less likely to have NPDR than the control group.

The prevalence and incidence of thyroid dysfunction in patients with diabetes - a longitudinal follow-up study

BACKGROUND

Thyroid dysfunction (TD) occurs in 13.4% of diabetic patients, which has prompted recommendations for annual thyroid screening in patients with diabetes. However, recommendations for annual screening should be based on disease incidence rather than prevalence.

METHODS

In 1997-1998, seven hundred and thirty patients (618 type 2 diabetes, 55% male; 112 type 1 diabetes, 47% male) were sequentially screened for TD. The 639 patients with normal thyroid function were followed from 1999 to 2006, with annual thyroid function tests.

RESULTS

A total of 21/112 (19%) with type 1 diabetes (T1DM) and 70/618 (11%) with type 2 diabetes (T2DM) had TD. TD was more frequent in females (p < 0.05) and T1DM (p = 0.04). The mean annual rate of conversion to abnormal tests was 2.1%. At 8 years, there were 100 new cases of TD representing 15.6% of the cohort (17 T1DM and 83 T2DM). TD was more frequent in females (p < 0.05), but there was no difference in the incidence of new TD between T1DM and T2DM (p = 0.39).

CONCLUSIONS

Our data confirms the high prevalence of TD in diabetic patients, in concordance with the results from other series. We found only 25 treatable cases of new thyroid disease from 639 patients in the 8-year follow-up, less than 0.5% per year. The low incidence of treatable thyroid disease challenges the need for annual screening for thyroid abnormalities in patients with type 2 diabetes.