|Year : 2021 | Volume
| Issue : 5 | Page : 211-215
Clinical evaluation of dyslipidemia among type 2 diabetes and hypothyroidism patients
Department of Pharmacology, GITAM Institute of Pharmacy, GITAM Deemed to be University, Visakhapatnam, Andhra Pradesh, India
|Date of Submission||24-Dec-2020|
|Date of Decision||12-Aug-2021|
|Date of Acceptance||31-Aug-2021|
|Date of Web Publication||30-Oct-2021|
Dr. Arun Koyyada
GITAM Institute of Pharmacy, GITAM Deemed to be University, Visakhapatnam, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
Aim: To evaluate the lipid profiles among type 2 diabetes and hypothyroid patients for establishing relation between dyslipidemia, diabetes and thyroid disorders.
Background: Dyslipidaemia is the leading cause of death in cardiovascular disease (CVD) patients. Diabetes and hypothyroidism are the two main endocrine risk factors for dyslipidaemia. Diabetes is associated with altered metabolism of triglyceride (TG) levels and low-density lipoprotein (LDL) levels. Hypothyroidism leads to decreased clearance of TG and catabolism of LDL.
Materials and Methods: This was a cross-sectional with 288 subjects that include normal population, diabetic and hypothyroid patients. The plasma lipid levels, thyroid profile and glucose levels were collected from the patients. The data were subjected to an unpaired t-test for statistical analysis. The P < 0.05 is indicative of statistical significance.
Results: The study included 288 patients out of which 104 were with type 2 diabetes, 81 were hypothyroid and 103 were controls. Dyslipidaemia cases found among them were 63, 26 and 32, respectively. The mean values of lipid levels in type 2 diabetes, hypothyroidism and control population were total cholesterol (TC) (211.4 ± 4.24, 190.5 ± 3.57 mg/dl and 187.3 ± 1.91 mg/dl), LDL (134.5 ± 3.01, 120.8 ± 2.035 and 115.8 ± 1.64 mg/dl), TG (188.6 ± 4.14, 169.9 ± 0.74 and 163.2 ± 2.42 mg/dl), high-density lipoprotein (HDL) (39.64 ± 0.45, 38.78 ± 0.49 and 38.64 ± 0.12 mg/dl) and non-HDL (171.75 ± 1.52, 151.75 ± 0.99 and 148.84 ± 1.99 mg/dl), respectively. Lipid levels of type 2 diabetes and hypothyroidism patients were found to be significantly more than the control population. The mean levels of TC, LDL, TG in type 2 diabetes and LDL, TG in hypothyroidism patients were found to be more than the normal range.
Conclusion: There was a significant relationship between type 2 diabetes, hypothyroidism and dyslipidaemia. Routine lipid profile monitoring in patients with diabetes and hypothyroid disorders is advisable for the primary prevention of dyslipidaemia and CVD.
Keywords: Cardiovascular disease, diabetes, dyslipidaemia, hyperlipidaemia, hypothyroidism, lipid profile
|How to cite this article:|
Koyyada A. Clinical evaluation of dyslipidemia among type 2 diabetes and hypothyroidism patients. Curr Med Res Pract 2021;11:211-5
| Introduction|| |
Dyslipidaemia is s by increased plasma lipid levels and promotes the development of atherosclerosis. This is considered one of the leading risk factors for cardiovascular diseases (CVDs). Hypercholesterolaemia is the main cause of atherosclerosis which may lead to ischaemic heart disease. In developed countries, most of the dyslipidaemias were found to be hyperlipidaemias. Hyperlipidaemia is classified as primary, caused by specific genetic abnormalities and secondary which is because of underlying disorders such as diabetes, chronic alcoholism, and hypothyroidism. Hyperlipidaemia has attained a significant interest among healthcare practitioners because of its association with CVD. During the past few years, CVD was recognised as a leading cause of death, particularly in the United States.
Diabetes and thyroid disorders are common endocrine disorders in the general population. Hypothyroidism is the most common of thyroid disorder with a high prevalence in females. Thyroid disorders can disturb the transport and composition of lipoproteins. Some studies show that hypothyroidism can lead to decreased consumption of oxygen by the heart which in turn leads to increased peripheral resistance and decreased contractility. Moreover, diastolic hypertension in addition with dyslipidaemia is accompanied with hypothyroidism leading to atherosclerosis.,, Thyroid hormones regulate wide array of metabolic parameters by affecting lipoprotein metabolism. Reduced activity of HMG CoA is seen in hypothyroid patients. Decreased thyroid hormone levels lead to decreased LDL receptor activity, clearance of triglycerides (TGs) and catabolism of LDL.
Diabetes was thought to associate with plasma lipoprotein abnormalities such as altered TG metabolism, increased hepatic very low-density lipoprotein secretion, increased production of precursors of LDL particles and increased efflux of free fatty acids from adipose tissue. In particular obese diabetic patients are at high risk of developing hyperlipidaemia. There was a 2–3 fold increased risk of CVD among diabetic patients. Metabolism of lipids and glucose is highly influenced by insulin. Impaired insulin action in diabetes can lead to increased intracellular hydrolysis of TGs, releasing non-esterified fatty acids, which in turn leads to complex alterations of plasma lipids. The LDL particles become small and dense which are more atherogenic than normal LDL particles. These are collectively responsible for CVD-related morbidity and mortality. The most common type of dyslipidaemia in type 2 diabetes subjects is elevated TG and decreased HDL levels. This study focuses on effects of diabetes and hypothyroidism on plasma lipid levels.
| Materials and Methods|| |
This was a cross-sectional study conducted in the Telangana region to compare the lipid profiles among type 2 diabetes (T2D), hypothyroidism and the control population. The total population screened in this study was 288 and the data were collected in well-designed case report forms. This design was established to determine the prevalence of dyslipidaemia in diabetes and hypothyroid patients. At the time of data collection, the patient's blood glucose levels (FBS, PLBS), fasting state lipid profile and thyroid profile were captured in the forms. The data were subjected to unpaired t-test for statistical analysis. The P < 0.05 is indicative of statistical significance. During the screening of patients, they were found to be on medication for their respective problems. Hypothyroid patients were on various doses of levothyroxine and T2D patients on oral anti-diabetics and some cases on insulin. Few patients were on lipid-lowering medication (statins) and the patients with concomitant hypertension were on antihypertensive drugs.
Normal range of lipid profile
- Total cholesterol (TC): <200 mg/dl
- Low-density lipoprotein (LDL): <100 mg/dl
- TG: <150 mg/dl
- High-density lipoprotein (HDL): >40 mg/dl
- Non-HDL cholesterol: 130–159 mg/dl.
Age group 20-60 years, patients with type 2 diabetes and overt hypothyroidism.
Normal group with no endocrine abnormalities.
Postmenopausal women and patients with other endocrine problems.
Compliance with ethical standards
This study's protocol was approved before the start of the study by the Human Institutional Ethics Committee. All procedures performed in our studies involving human participants were designed and carried out in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 declaration of Helsinki and its later amendments.
| Results|| |
The total number of patients involved in this study was 288. Among them 104 were with T2D, 81 were with hypothyroidism and 103 were the control population. The lipid profile of the T2D, hypothyroidism patients and control population were taken and the number of dyslipidaemia cases among 287 patients is 121, of which 63, 26 and 32 in diabetics, hypothyroid and control population, respectively. [Table 1] shows the gender-wise distribution of dyslipidaemic patients among T2D, hypothyroidism and control population. The female population getting dyslipidaemia was found to be greater than that of males in all the classified groups.
|Table 1: Gender wise distribution of dyslipidemic patients among the study subjects|
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The plasma glucose levels of dyslipidaemia cases in the controls (n = 32) were compared with cases in T2D (n = 63) and the results found were FBS (92.69 ± 3.75, 149.3 ± 3.84; P < 0.0001), PLBS (138.1 ± 5.48, 219.0 ± 3.24; P < 0.0001) of control subjects and diabetic patients, respectively. The mean blood glucose levels were significantly more in diabetic patients than controls. This shows the correlation between T2D and lipid levels. The TSH levels of dyslipidemia cases in controls and hypothyroidism patients (n = 26) were compared and the results were found to be 2.72 ± 1.74, 16.34 ± 2.54, respectively. The mean TSH levels in hypothyroid patients were found to be significantly more (with P < 0.0006) than the controls, indicating the relation between hypothyroidism on plasma lipids. The lipid profile of the diabetics and hypothyroid patients were compared with that of the control population. The mean values were TC (211.4 ± 4.24, 187.3 ± 1.91 mg/dl), LDL (134.5 ± 3.01, 115.8 ± 1.64 mg/dl), TG (188.6 ± 4.14, 163.2 ± 2.42 mg/dl), HDL (39.64 ± 0.45, 38.64 ± 0.12 mg/dl) and non-HDL (171.75 ± 1.52 mg/dl, 148.84 ± 1.99 mg/dl) of T2D patients and control population, respectively. The lipid levels in T2D patients were found to be significantly more than in the control population. The comparison of diabetic lipid profile with that of control population is given in [Table 2].
|Table 2: Lipid profile comparison between diabetic patients and control subjects|
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In hypothyroidism patients the mean values of lipid profile were TC (190.5 ± 3.57 mg/dl), LDL (120.8 ± 2.035 mg/dl), TG (169.9 ± 0.74 mg/dl), HDL (38.78 ± 0.49 mg/dl) and non-HDL (151.75 ± 0.99). These values are compared with that of the control population. The lipid levels in hypothyroidism patients were found to be significantly more than in the control patients. This data were shown in [Table 3]. The comparison of lipid profile between the control population, T2D and hypothyroidism patients is depicted in [Figure 1].
|Table 3: Lipid profile comparison between hypothyroid patients and control subjects|
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|Figure 1: Comparison of lipid levels in diabetics, hypothyroid and normal population|
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The lipid levels of the T2D and the hypothyroidism patients were subjected to an unpaired t-test. The levels in the diabetic patient were significantly greater than that of hypothyroidism. [Table 4] and [Figure 2] show the comparison of lipid profile between diabetic and hypothyroid patients. The lipid levels were found to be more among T2DM than the hypothyroidism patients.
|Table 4: Comparison of lipid profile between type 2 diabetics and hypothyroid patients|
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| Discussion|| |
This study was carried out to compare the lipid levels in the control people with that of T2D and hypothyroidism patients. The prevalence of dyslipidaemia among T2D and hypothyroidism was found to be 48.1% (n = 89) and dyslipidaemia in controls was found to be 31.1% (n = 32). This shows a strong relationship between plasma lipids and T2D, hypothyroidism disorders. The results showed a significant number of dyslipidaemia cases in T2D and hypothyroidism patients when compared with that of control individuals. There were 31.1% dyslipidaemias among the control group versus 60.57% among T2DM and 32.09% among hypothyroidism patients. There was a significant difference in the percent of dyslipidaemias between the control group and diabetic group (31.1% vs. 60.57%), but there was no significant difference in the percent of dyslipidaemias between the control group and hypothyroidism group (31.1% vs. 32.09%). This shows an increased prevalence of secondary hyperlipidaemia which was due to underlying diabetes and hypothyroidism. The increased levels of blood glucose and TSH (in hypothyroidism) significantly affect the plasma lipid profile leading to dyslipidaemia. The lipid profile including TC, LDL, TG, HDL and non-HDL were found to be significantly more in T2D and hypothyroidism patients when compared with the control population.
The results of this study have shown increased levels of TC, LDL and TG in T2D patients than the normal range, whereas the HDL levels were found to be low. In hypothyroidism patients, the levels of LDL and TG were found to be more. In supporting this, Shin, et al. have reported the hypothyroidism linked hypercholesteraemia with increased levels of LDL and reduced LDL uptake in the liver. This can be reversed by adding T3 (triiodothyronine), showing that the effective treatment of hypothyroidism can prevent the hyperlipidaemia. Improvement in lipid profiles can be achieved by thyroxine therapy at a TSH suppressive dose. The guidelines of the National cholesterol education programme recommend screening for hypothyroidism in newly hyperlipidaemia diagnosed patients. About 1.4%–13% of hyperlipidaemia patients were presented with hypothyroidism. Abbate and Brunzell in their study reported that the hyperglycaemic diabetic patients commonly have mild hypertriglyceridemia due to overproduction of TG-rich lipoproteins in the liver.
The diabetic patients were likely to have hypertension as a co-morbid condition. In this study, few patients with hypertension were treated with antihypertensive drugs. These drugs can affect lipid metabolism which ultimately leads to the risk of cardiovascular disease. It was also recommended that the necessity of monitoring lipid profile before initiating antihypertensive therapy. The increased lipid levels in this study could be impacted by antihypertensive drugs. However, the relation between antihypertensive drugs and cellular lipid metabolism was not yet known clearly. Another limitation of this study was the use of statins among few patients. However, the statins have not controlled the lipid levels among patients with diabetes and hypothyroidism. This could suggest the strong impact of both disorders on lipid metabolism and also the change in dose or the choice of drug among them. The other major limitation of this study remains with not accounting for the impact of anti-diabetics and/or insulin and levothyroxine treatment on lipid profiles among T2D and hypothyroidism patients. These major limitations of this study further suggest the researchers to take it as an active area of interest.
Management of dyslipidaemia, a modifiable risk factor is a key element to prevent CVD in patients with diabetes. Moreover, American Diabetic Association in 2015 recommended that diabetic patients of age >40 years should be treated with statins and lifestyle modifications. Atorvastatin was found to be a significant regimen in preventing cardiovascular events and death. There was a well-established association between dyslipidaemia and risk of CVD. Therefore, the patients with diabetes should be cautious about their lipid levels. Controlling diabetes with proper medication can reduce the risk of dyslipidaemia in patients.
| Conclusion|| |
Dyslipidaemia is the leading cause of death due to CVD. The secondary hyperlipidaemia due to diabetes and thyroid disorders can be manageable. Routine lipid profile monitoring in patients with diabetes and hypothyroid disorders is advisable for the primary prevention of dyslipidaemia. Patients with diabetes and thyroid disorders should take proper treatment to keep their glucose levels and thyroid hormone levels in normal so that the plasma lipids will be in control. Early diagnosis and treatment can prevent CVD and deaths. Patients with diabetes should be encouraged for lowering their lipids by controlling blood glucose levels, weight loss, exercise and by maintaining the appropriate diet.
This study has the potential to influence the researchers for further clinical studies on various risk factors and their mechanisms influencing the association of diabetes and thyroid with plasma lipids. By early analyses of lipid profiles in clinical practice among diabetic and thyroid patients can minimise the risks of dyslipidaemia cases. Clinical pharmacists as a part of patients health care team can play a key role in assessing the patient's medical history of diabetes, thyroid and can suggest to the physician about the possible dyslipidaemia condition and treatment strategies.
The author expresses his thanks to Dr. Bathula Sridhar, MD (Endocrinology), Samraksha Hospital, Warangal and Dr. S. Gurunath, Principal, Vaagdevi Institute of Pharmaceutical Sciences for their support in the accomplishment of this study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]