Background: Thyroid hormones elicit significant cardiovascular effects, and abnormalities of its concentration may lead to palpitations. This study seeks to evaluate the prevalence of thyroid hormone disorders in adult Nigerians with palpitations. Materials and Methods : A total of 62 patients (20 males, aged 36.8 ± 10.0 years and 42 females, aged 39.3 ± 9.9 years) with palpitations referred to the chemical pathology laboratory for biochemical analysis from June 2002 to May 2007 were retrospectively studied. All blood specimens were routinely collected in the morning in fasting state. The thyroid function parameters were analyzed using ELECSYS 1010 autoanalyzer supplied by Roche Diagnostics, Germany. The analyzer uses the principle of electrochemiluminescence immunoassay technique. Results : Out of the 62 patients, 10 (4 males and 6 females) had thyroid disorders representing a prevalence of 16.1%. Conclusions: Prevalence of 16.1% was observed in patients with palpitations. More women than men were observed to have palpitations and the ratio of proportion of thyroid disorders between male and female was 2:3.
Keywords: Palpitations, thyroid stimulating hormone, thyroxine, triiodothyronine
|How to cite this article:
Emokpae MA, Osadolor HB, Uwumarongie HO. Thyroid disorders in adult Nigerians with palpitations. Ann Trop Med Public Health 2012;5:111-3
|How to cite this URL:
Emokpae MA, Osadolor HB, Uwumarongie HO. Thyroid disorders in adult Nigerians with palpitations. Ann Trop Med Public Health [serial online] 2012 [cited 2020 Aug 5];5:111-3. Available from: https://www.atmph.org/text.asp?2012/5/2/111/95964
Heart palpitation is a common phenomenon in man. It occurs in the form of skipped heart beats, heart beats that are faster than normal, pumping harder than usual or heart beats that give a fluttering feeling. Others defined heart palpitations as an increased or abnormal awareness of ones heart beats and are relatively common complaints for patients presenting to family physicians.  These conditions are generally harmless but may raise concern when persistent, which may be a manifestation of heart conditions.  Palpitations can be caused by a variety of cardiac and non-cardiac problems. Most palpitations are caused by cardiac arrhythmias (heart beats that are too slow, too rapid, irregular or too early), anxiety, drug overdose or thyroid disorders. , Palpitations can be benign or symptomatic of life-threatening cardiac conditions. Thyroid hormones elicit significant cardiovascular effects and abnormalities of its concentration may lead to cardiovascular disease and mortality.  Several studies have suggested that abnormalities in thyroid homeostasis contribute to progression of heart diseases caused by various etiologies.  Previous studies have shown that thyroid hormones are required for the development and maturation process of organ tissues and T 3 /T 4 ratio in the euthyroid subjects been used as possible biochemical marker of assessment of endemic goiter. ,, Both excess and deficiency of thyroid hormones produce metabolic and cardiovascular disturbances even in mild thyroid dysfunction.  Because there is no consensus or evidence-based guidelines for diagnosing and managing palpitations, studies of its etiologies provide evidence that can guide physicians through diagnosis.  Clinicians may order thyroid hormone evaluation after clinical, physical examination and obtaining electrocardiogram in order to diagnose palpitations caused by thyroid disorders. There is no information on the prevalence of thyroid hormone disorders in patients with palpitations from this center. This study therefore seeks to evaluate the prevalence of thyroid hormone disorders in adult Nigerians with palpitations in Kano, Northern Nigeria.
|Materials and Methods|
The study was conducted at Aminu Kano Teaching Hospital, a referral tertiary hospital located in Kano, Nigeria. This is a retrospective study of 62 patients with palpitations referred to the chemical pathology laboratory for biochemical analysis from June 2002 to May 2007. The laboratory and other medical information were obtained from the patients’ health records. The subjects consisted of 20 males, mean aged 36.8 ± 10.0 years and 42 females mean aged 39.3 ± 9.9 years. Analysis of laboratory results of triiodothyronine (T 3), thyroxine (T 4) and thyroid-stimulating hormone (TSH) were made. If a patient had more than one thyroid profile ordered within the study period, only the first was included in the analysis. Those who are known to have thyroid disease were excluded. All blood specimens were routinely collected in the morning in fasting state. The thyroid function parameters were analyzed using ELECSYS 1010 autoanalyzer supplied by Roche Diagnostics, Germany. The analyzer uses the principle of electrochemiluminescence immunoassay technique.
Data were expressed as mean ± SD. Student’s t-test for unpaired means was used for statistical analysis. Values were considered statistically significant at P<0.05.
The results of thyroid hormones in patients with palpitations are shown in [Table 1] and [Table 2]. Out of the 62 patients with palpitations retrospectively studied, 20 were males while 42 were females. Ten of the patients had thyroid hormone disorders representing a prevalence of 16.1%. The mean age of patients was 32.7 ± 9.7 years. The thyroid hormone levels were T 3 = 2.49 ± 1.5 nmol/L, T 4 = 141 ± 58.0 nmol/L and TSH = 1.32 ± 1.1 μIU/mL. The reference ranges used routinely in the hospital were T 3 (1.3-3.1 nmol/mL); T 4 (66-181 nmol/mL) and TSH (0.27-4.2 μIU/mL) [Table 1].
|Table 1: Thyroid hormones in patients with palpitations
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|Table 2: Characteristics of study patients on the basis of thyroid hormone levels
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Out of the 10 subjects with thyroid disorders, 4 were males while 6 were females. All four males had hyperthyroid hormone levels while 4 females had hyperthyroid and 2 had hypothyroid hormone levels. The patients with hyperthyroid hormone levels had mean age 48.1 ± 2 years, which was significantly higher (P<0.005) compared with those patients with euthyroid hormone levels. The subjects with hyperthyroid hormone levels had mean T 3 value of 4.6 ± 1.1 nmol/mL, T 4 254.3 ± 32.7 nmol/L and TSH 0.53 ± 0.5 μIU/mL. When these mean values were compared with the mean values in patients with euthyroid hormone levels, statistically significant differences (P<0.001; P<0.001 and P<0.005) were observed, respectively. In the patients with hypothyroid hormone levels, the mean age was 40 ± 6.2 years, hormone values were T 3 = 1.92 ± 1.0 nmol/mL, T 4 = 131 ± 6.0 nmol/mL and TSH = 5.06 μIU/mL. Statistically significant difference was observed for TSH (P<0.001) only when compared with mean value in the patients with euthyroid hormone levels. The overall prevalence of thyroid hormone disorders among the male subjects was 6.5% while the female was 9.7% giving ratio of proportion of thyroid hormone disorders between male and female to be 2 : 3.
The overall prevalence of thyroid disorders in adult Nigerians with palpitations from this study was 16.1%. High circulating levels of thyroid hormones can alter most organ systems of the body. Thyroid hormones have positive chronotropic and inotropic effects on the heart. Hyperthyroidism cause increased cardiac output and cardiac rate. These effects result from increased demand of oxygen in peripheral tissues and increased blood flow to the skin, muscles and kidneys. , Clinical studies have shown that such patients manifest a tachycardiac and a bounding pulse and the widened pulse pressure both of which increased cardiac output and decreased peripheral vascular resistance. , Thyroid disorders if untreated can manifest or exacerbate pre-existing cardiac pathology. , Ansari et al, reported that about 68% of hyperthyroid patients had different types of cardiac pathology.
Studies of palpitation etiologies provide improved evidence that can guide physicians through diagnosis.  In a prospective study  of 190 patients with palpitations, followed for one year, it was observed that etiology was determined in 84% of the patients. Of these patients, 43% had palpitations caused by cardiac causes, 31% had palpitations caused by anxiety or panic disorder while 6% had palpitations caused by drug overdose and 4% had palpitations caused by non-cardiac causes such as thyroid disorder. No specific cause of palpitations could be identified in 16% of the patients. This observation of 4% cause of palpitation due to thyroid disorders is lower than 16.1% observed in our study. Thyroid disease can mimic a variety of complaints, the clinicians must maintain a high degree of suspicion for thyroid disease as its signs and symptoms could be mistaken for other common diseases.  It was observed that hyperthyroidism and hypothyroidism were involved in patients with palpitations. This is consistent with the report that both excess and deficit in thyroid hormones produce metabolic and cardiovascular disturbances.  It was therefore concluded that it is important that their pathogenesis, recognition and treatment be considered.
Prevalence of 16.1% was observed in patients with palpitations. Assessment of thyroid hormones may be necessary in evaluating patients with palpitation. More women than men were observed to have palpitations and the ratio of proportion of thyroid disorders between male and female was 2 : 3.
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Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2]