This study examined the relationship between thyroid dysfunction and insulin resistance by comparing insulin resistance levels in hyperthyroid, hypothyroid, and euthyroid patients. The results showed that hypothyroid patients had the highest levels of insulin and insulin resistance as measured by HOMA-IR. Hyperthyroid patients also had higher levels than euthyroid patients. Specifically, hypothyroid patients showed a positive correlation between TSH levels and insulin resistance, while hyperthyroid patients showed a correlation between FT3 levels and insulin resistance. The study concluded that thyroid disorders are associated with greater insulin resistance and risk of cardiovascular and metabolic abnormalities.

1. Impact of Thyroid Dysfunction
on Insulin Resistance: A Study
from a Tertiary Care Center in
India
Journal of The Association of Physicians of India ■
Vol. 69 ■ February 2021
Swati Srivastava, Girish Mathur, Gaurav Chauhan,
Priyanka Kapoor Et al

2. INTRODUCTION
THYROID GLAND
• The thyroid gland consists of two lobes connected by an
isthmus. It is located anterior to the trachea between the cricoid
cartilage and the suprasternal notch. The normal thyroid is 12–
20 g in size, highly vascular, and soft in consistency. Four
parathyroid glands, which produce parathyroid hormone, are
located posterior to each pole of the thyroid.

3. INTRODUCTION
• The thyroid gland produces two related hormones, thyroxine
(T4) and triiodothyronine (T3). Acting through thyroid hormone
Receptors alpha and beta , these hormones play a critical role
in cell differentiation and organogenesis during development
and help maintain thermogenic and metabolic homeostasis in
the adult.

8. INSULIN RESISTANCE
• Insulin resistance is when cells in muscles, fat, and
liver donot respond well to insulin and cannot use
glucose from blood for energy. In response
pancreas makes more insulin. Over time blood
sugar levels go up.
• Insulin resistance syndrome includes a group of
problems like obesity, high blood pressure, high
cholesterol, and type 2 diabetes.

9. THYROID DYSFUNCTION AND INSULIN RESISTANCE
Thyroid hormone abnormalities disturb the fine balance of
insulin sensitivity and lead to alterations of glucose
metabolism. Thyroid disorders occur more frequently in
patients suffering from diabetes mellitus with the prevalence
being 13.4%.
Thyroid hormone excess leads to glucose intolerance and
sometimes precipitation of diabetic ketoacidosis.

10. OBJECTIVE
• To study the correlation between insulin resistance
and thyroid status in hyperthyroid, euthyroid, and
hypothyroid individuals.

11. METHEDOLOGY
• Study design : Observational comparitive Study.
• Study Setting : The 3 study groups comprised of 35 patients each with
newly detected hyperthyroidism, hypothyroidism and euthyroid
individuals attending in the SMS Medical College and attached group
of Hospitals, Jaipur.

12. Sample size and subject selection
The subjects were included in 3 groups
• Group A : 35 newly detected hyperthyroid cases attending the
outdoor or indoor wards of SMS Hospital were included.
• Group B: 35 newly diagnosed hypothyroid cases were included.
• Group C: 35 euthyroid individuals were included in this group.

13. INCLUSION CRITERIA
• Individuals of age more than 18 years.
• Adults (Male or female) who were newly diagnosed as hyperthyroid
and hypothyroid.

14. EXCLUSION CRITERIA
• Patients with known history of diabetes mellitus, polycystic ovarian
disease, on drugs affecting insulin resistance, with previous history of
thyroid disorder and treatment were excluded from the study.
• Pregnant and lactating women also were excluded.

15. Study Procedure
• 1. The newly detected cases of hypothyroid and hyperthyroid
attending the outpatient department or admitted to medicine ward
were selected according to inclusion and exclusion criteria.
• 2. Standard tests were used to analyze various parameters like Blood
glucose, serum insulin, thyroid hormones, lipid profile, Complete
blood count, liver and kidney function test.
• 3.The homeostasis model assessment (HOMA) for insulin resistance
(HOMA-IR) using the mathematical modeling of insulin
concentrations and fasting plasma glucose was estimated.

16. RESULTS
• The mean age of hypothyroid patients was 44.37 years, euthyroid
patients was 43.86 years, hyperthyroid patients was 45.24 years.
Gender wise distribution showed that in the study, 32 subjects were
male and 73 subjects were female.
• The difference in mean hemoglobin, total leukocyte count, blood
urea, creatinine, total bilirubin, AST level, ALT levels, total proteins,
serum albumin, serum globulin levels among study groups were not
statistically significant.

17. RESULTS
• The mean fasting blood glucose was highest in hyperthyroid group
followed by hypothyroid group with the difference in mean fasting
blood glucose among study groups being statistically significant.
• The mean HbA1C was highest in hyperthyroid group and application
of ANOVA test showed that difference in mean HbA1C level among
study groups was statistically significant.

19. RESULTS
• The mean insulin was highest in hypothyroid group (15 ± 12 µIU/ ml)
followed by hyperthyroid group (10.38 ± 7.56 µIU/ml) and lowest in
euthyroid group (4 ± 3µIU/ml).
• The mean HOMA-IR was highest group in hypothyroid group (3 ±
2.69) followed by hyperthyroid group (2.2 ± 1.59) and lowest in
euthyroid (0.79± 0.58).

21. RESULTS
• The mean HOMA-IR was highest in patients with hypothyroidism
(3.22 ± 2.69) followed by the hyperthyroid group (2.25 ± 1.59). It was
lowest in the euthyroid group (0.79 ± 0.58) with the intergroup
difference being statistically significant (P<0.001).
• Hypothyroid patients showed a significant a positive correlation
between TSH and HOMA-IR, whereas hyperthyroid patients showed
positive correlation between FT3 and insulin resistance

22. DISCUSSION
• Thyroid hormones have impact on metabolism, energy dissipation
and insulin sensitivity. Insulin resistance refers to reduced sensitivity
of body tissues like the adipose tissue, muscles even with high or
normal levels of insulin in the blood. Increasing body of evidence
suggests a pattern of multiform combination of biochemical,
inherited, and endocrinal defects leading to this pathophysiological
interdependence.
• A possible mechanism suggests reduced blood flow to the peripheral
tissues in hypothyroid patients to be accounting for the presence of
insulin resistance in these patients.

23. DISCUSSION
• T3 and insulin have similar sites of impact at the cellular and
molecular levels in the metabolism of glucose. Hence even minor
alterations in the thyroid hormone levels even within the euthyroid
range may show insulin resistance.
• The bilateral impact between thyroid function and diabetes mellitus
has significance in the clinical outcome. It could be hypothesized that
correction of thyroid abnormalities in patients suffering from diabetes
will enhance glycemic control, diminish cardiovascular risk, and
strengthen overall health.

24. LIMITATIONS
• Being a cross sectional study, the study was not done on the impact
of correction of thyroid hormone abnormalities on insulin resistance.
Follow up studies would be further enhance our understanding of the
relationship between these two parameters. Also, larger study
population could help us endorse the validity of these findings.

25. CONCLUSION
• The significant positive correlation between TSH and HOMA-IR as well
as insulin in patients suffering from hypothyroidism. Serum insulin,
HOMA-IR showed positive correlation with FT3 in patients with
hyperthyroidism. We documented statistically significant higher
insulin resistance in patients with hypothyroidism, hyperthyroidism in
comparison with the euthyroid individuals.
• These findings testify greater hazard of cardiovascular and metabolic
abnormalities accompanying insulin resistance in patients with
thyroid disorders and justifies the significance to screen patients with
thyroid disorders for evidence of metabolic disorders.

26. THANK YOU