|Ahead of print publication
Risk of cardiovascular changes in hypothyroidism in North-west Punjab population
Gagandeep Jagota1, Rajinderjit Singh Ahi2, Rakendra Singh3, Saranpal Singh2
1 Centre for Interdisciplinary Biomedical Research, Adesh Institute of Medical Sciences and Research, Adesh University, Bathinda, Punjab, India
2 Department of Biochemistry, Adesh Institute of Medical Sciences and Research, Adesh University, Bathinda, Punjab, India
3 Department of Medicine, Adesh Institute of Medical Sciences and Research, Bathinda, Punjab, India
|Date of Submission||19-Nov-2019|
|Date of Decision||05-Jan-2020|
|Date of Acceptance||11-Mar-2020|
Rajinderjit Singh Ahi,
Department of Biochemistry, Adesh Institute of Medical Sciences and Research, Adesh University, Buchu Kalan, Bathinda, Punjab
Source of Support: None, Conflict of Interest: None
Background: This study was done with an objective to study the cardiovascular involvement associated with newly detected overt and subclinical hypothyroidism. Methods: A total number of 150 newly detected hypothyroid patients, diagnosed by the clinical evaluation, confirmed by thyroid hormone assay, were subjected to electrocardiograph and echocardiography. It was a cross-sectional study design based on the random sampling method, which was conducted for 2 years in the Central Laboratory of Adesh Institute of Medical Sciences and Research and Center for Interdisciplinary Biomedical Research, Adesh University. Results: Of 150 patients studied, 62 were overt hypothyroid and 88 were subclinical hypothyroid. Forty-one were male and 109 were female. Hypothyroidism was newly diagnosed more in females and maximum in the age group of 41–70 years (69.9%). Of 150 patients, 63.3% had symptoms <2-month duration. Cardiovascular symptoms were present in 68.0% of patients. Bradycardia was observed in 44.0% of patients. Stage 1 hypertension was noticed in 30.7% (systolic high blood pressure). Low-voltage complexes in electrocardiogram (ECG) were present in 34.0% study group. Pericardial effusion was present in 32.7% of patients. Diastolic dysfunction was noticed in 20.0% study group. Altered lipid profile was present in 74.0% (total cholesterol) and 65.3% (total triglycerides). Conclusions: Hypothyroidism is common in female, maximum between the age group of 17 and 47 years. Majority of the patients have cardiovascular changes such as ECG abnormalities, pericardial effusion, diastolic hypertension, and diastolic dysfunction. Systematic study was done to know the early effects of hypothyroidism on cardiovascular system. The identification of patients with hypothyroidism is an important individual as well as public health issue. Hence, early detection and initiation of hormone replacement therapy can minimize the associated cardiovascular changes.
Keywords: Cardiovascular, hypothyroidism, overt and subclinical hypothyroidism
|How to cite this URL:|
Jagota G, Ahi RS, Singh R, Singh S. Risk of cardiovascular changes in hypothyroidism in North-west Punjab population. Med J DY Patil Vidyapeeth [Epub ahead of print] [cited 2021 Mar 2]. Available from: https://www.mjdrdypv.org/preprintarticle.asp?id=308719
| Introduction|| |
Hypothyroidism is the most common functional disorder of the thyroid gland. It is due to decreased secretion of thyroid hormones or impaired activity of tissue due to thyroid gland failure or disorder of the pituitary gland or hypothalamus.
Overt hypothyroidism is defined as elevated serum thyrotropin (thyroid-stimulating hormone [TSH]) concentration and serum T4 (free thyroxine) below the reference range, while subclinical hypothyroidism is defined as an elevated serum TSH value associated with a serum-free T4 within the reference range.
Thyroid hormones have cellular effects on almost all tissues of the body which causes multiorgan dysfunction.,, Cardiovascular complications are some of the most profound and reproducible clinical findings associated with thyroid disease. Hypothyroidism is associated with increased cardiovascular mortality and morbidity. The dysfunction ranges from functional systolic/diastolic dysfunction to overt failure. A systematic study was done to know the early effects of both overt and subclinical hypothyroidism on the cardiovascular system. The identification of patients with both overt and subclinical hypothyroidism is an important individual and public health issue which can minimize the associated cardiovascular changes.,
Hence, this study was done with an objective to study the cardiovascular involvement associated with newly detected overt and subclinical hypothyroidism.
This study was done with an objective to study the cardiovascular involvement associated with newly detected overt and subclinical hypothyroidism.
| Methods|| |
It was a cross-sectional study design based on the random sampling method, which was conducted for 2 years in the Central Laboratory of Adesh Institute of Medical Sciences and Research, and Centre for Interdisciplinary Biomedical Research, Adesh University. This study was conducted after taking institutional ethical clearance from the Ethics Committee of Adesh University, Bathinda (Ref. no.: AU/EC/FM/41/2018, dated January 20th, 2018) and informed consent of the patients. The study population was diagnosed by clinical evaluation and confirmed by thyroid hormone assay reference ranges TSH (0.39–5.50 μIU/ml), total T4 (4.5–10.9 μg/dl), and total T3 (0.60–1.80 ng/dl). Patients with TSH >20 μIU/ml and low total T4 were considered overt hypothyroidism, and TSH ranging (4.2–20 μIU/ml) were considered subclinical hypothyroidism.
All patients of newly detected hypothyroidism diagnosed by clinical evaluation and confirmed by serum TSH, T4, and T3 level.
Hypothyroid patients who were already on treatment; patients on antihypertensives, steroids, glucocorticoids, antineoplastic drugs, nonsteroidal anti-inflammatory drugs; and patients with other diseases such as diabetes, pernicious anemia, collagen disorders, cardiac diseases, and other endocrine disorders, moreover, pregnant women were also excluded from the study.
The following investigations were done to diagnose hypothyroidism and cardiac profile: random blood sugar, serum T3, T4, TSH, lipid profile, electrocardiogram (ECG), and two-dimensional (2D) echocardiogram (Echo).
The analysis of the data was made on the basis of measures of central tendency, dispersion and graphical representation of the data, mean deviation, standard error, and Chi-square test. P < 0.05 was considered statistically significant.
| Results|| |
Of 150 patients studied, 62 (41.3%) were overt hypothyroid and 88 (58.7%) were subclinical hypothyroid. Forty-one were male and 109 were female. Hypothyroidism was newly diagnosed more in females and maximum in the age group of 41–70 years.
Cardiovascular symptoms were seen in 98 (65.3%) patients, which include effort intolerance in 98 (65.3%), chest pain 43 (28.7%), breathlessness 57 (38.0%), and palpitation in 68 (45.3%) patients each [Table 1].
Prehypertension (systolic) was present in 28 males and 38 females which constituted 66 (44.0%) of the total population. Stage 1 systolic hypertension is present in 36 (24.0%) and Stage 2 systolic hypertension is present in 14 (9.3%) [Table 2].
Prehypertension (diastolic) was present in 24 males and 89 females which constituted 75.3% of the total population. Similarly, Stage 1 diastolic hypertension was present in 13.3% of the study group and Stage 2 diastolic hypertension was present in 4.7% of the study group [Table 3].
Lipid profile in this study revealed 111 (74.0%) of patients had high serum total cholesterol. Ninety-eight (65.3%) had high serum triglyceride, 36 (24.0) had higher low-density lipoproteins, lower high-density lipoproteins in 65.3% patients, and higher very low-density lipoproteins in 58.0% [Table 4].
In this study, low voltage complexes in ECG were found in 24 (60%) of patients, of which 6 (10%) were male and 18 (30%) were female. Similarly, 15% of males had T-inversion in V3–V6 leads [Table 5].
ECG findings were normal in 43.3% of patients. Bradycardia was commonly seen in 44.0%, ST segment changes in 36.0%, low-voltage complexes in 34.0% patients, and T-wave (flat/inverted) in 31.3% patients.
2D Echo findings were normal in 33% of cases. Diastolic dysfunction and pericardial effusion were found in 16 (26.6%) cases followed diastolic dysfunction in 16 (26.6%), systolic dysfunction in 4 (6.6%), and increased interventricular septum spectrum thickness 4 (6.6%) cases. Majority of the diastolic dysfunction were mild dysfunction. No cases found to have severe diastolic dysfunction [Table 6].
| Discussion|| |
This study included 150 newly detected patients with hypothyroid. The patient's age range was 20–70 years in the study. Most patients belonged to the age group of 31–70 years. Overall, there was a female preponderance over the age of 31–70 years. The female population constituted about 72.7% of the total, that is, female: male ratio 3:1.
On general examination, the commonly found symptoms were easy fatigability 56.9% in males and 63.2% in females; weight gain 54.5% in males and 45.3% in females; aches and pain 53.1% in males and 32.8% females; menorrhagia 43.1% in females, dry skin in 22.0% in males and 36.3% in females; intolerance too cold around 31.3% in males and 42.7% in females; swelling of limbs in 39.2% in males and 32.1% in females; puffiness of face in 26.7% in males and 26.9% in females; chest pain 24.9% in males and 30.0% in females; and breathlessness 17.7% in males and 20.0% in females. These results were similar as compared to the results of Shashi and Watanakunakorn.,,
On general examination, the general signs include body mass index >25 kg/m2 in 73.2% males and 56.0% females, thyromegaly seen in 30% of females, delayed ankle jerk in 14.6% males and 27.5% females, and lower limb edema in 29.3% males and 47.7% females.
In our study, diastolic dysfunction was seen in 18%, but in a study by Verma, it was seen that 27% of patients had diastolic dysfunction. Systolic dysfunction was seen in 33.3% of patients, but Forfar et al. and others have described low systolic function indices in hypothyroid patients; however, Fouron et al., Grossman et al., and Verma et al. did not find any evidence of systolic dysfunction in hypothyroid patients.,,, Rawat and Satyal showed no systolic dysfunction. Zoncu et al. found impairment in both systolic and diastolic function in subclinical hypothyroidism.
In this study, there is an increase in the levels of total cholesterol, low-density lipoprotein, very low-density lipoprotein, and triglycerides and decrease in the levels of high-density lipoprotein. Alka et al. Shende et al. and Williams's Textbook of Endocrinology showed increase of total cholesterol.,,
In ECG changes, bradycardia was present in 44%, low-voltage complexes in 34%, followed by “T”-wave (flat/inverted) changes 31.3%, and ST segment changes in 36.0%. This finding is not consistent with other studies by Varma et al. Nikoo also documented sinus tachycardia, QT prolongation, and ventricular tachycardia, which was not found in our study.,
In 2D echo changes, left ventricular diastolic dysfunction was abnormal in 17.3%, pericardial effusion in 32.7%, LWH in 25.4%, RWMA in 7.4%, and ejection fraction (<50%) in 34.7%. This finding is consistent with other studies of Verma et al. that showed the prevalence of effusion to be 22.75%. Pericardial effusion is reported to occur in 30%–80% of patients with hypothyroidism Rawat and Satyal. Some studies show a relatively low incidence of pericardial effusion, which may be due to the selection of new hypothyroid.,,
In this study, major manifestations were dyslipidemia, systolic and diastolic hypertension, ECG changes [Table 7], and ECHO changes. There was a statistically significant association between degrees of hypothyroidism and all these manifestations.
| Conclusions|| |
Cardiovascular symptoms and signs were present in hypothyroid patients. Hence, a high index of suspicion is the key to the early diagnosis of hypothyroidism. Cardiovascular disease is highly associated with newly detected hypothyroidism. The occurrence of cardiovascular disease in hypothyroidism is significantly related to the duration of disease, so there is a need for the early diagnosis of hypothyroidism. Hence, electrocardiogram, echocardiogram, and lipid profile are the investigation of choice for the diagnosis of cardiovascular disease. Early identification, diagnosis, and correction of hypothyroidism are necessary, so that early effects on cardiovascular disease can be minimized.
The help provided by the Chairperson, Centre for Interdisciplinary Biomedical Research, Adesh University, is gratefully acknowledged.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]