European Journal of Cardiovascular Medicine

Nonalcoholic fatty liver disease (NAFLD) is defined by imaging and histological evidence of abnormal fat deposition in the liver and does not result from substantial alcohol use or any other known secondary cause.1 Nonalcoholic steatohepatitis (NASH) ranges from isolated hepatic steatosis (IHS) to cirrhosis and hepatocellular carcinoma, which are severe types of NASH characterized by inflammation and cellular destruction.2 This syndrome increases the incidence of chronic liver problems as well as the requirement for liver transplantation.3

Patients with NASH are more likely to die from NAFLD and its extra-hepatic effects, which include systemic metabolic syndrome, chronic renal disease, cardiovascular disease, and cancer.4 NAFLD's significance in the greater context of health is emphasized by its close association with obesity and related metabolic disorders such as insulin resistance and dyslipidemia.

The development and progression of NAFLD are influenced by a combination of environmental factors, inter-patient genetic and epigenetic variations, and the illness itself.5 the current theory on the origin of NAFLD is that insulin resistance, which is often linked with obesity, promotes lipid accumulation in the liver. The reasons of this accumulation include adipose tissue FFA flow to the liver, dietary fat via chylomicron metabolism, and increased de novo lipogenesis.6-8 Obesity-induced low-grade inflammation causes immune cells, particularly macrophages, to accumulate in adipose tissue. Insulin resistance develops in the liver and throughout the body, in part because adipocytes produce proinflammatory cytokines.9,10 Nonalcoholic steatohepatitis (NASH) and fibrosis, on the other hand, are caused by a series of events described as "Multiple hits," which include mitochondrial dysfunction, alterations in the gut-liver axis, endotoxins, and oxidative stress.5 Obesity, increasing age, and other metabolic disorders are commonly believed to be significant contributors to the global rise in nonalcoholic fatty liver disease. Nonalcoholic fatty liver disease has been associated with the following conditions: polycystic ovarian syndrome, metabolic syndrome, diabetes mellitus, hypothyroidism, hypopituitarism, hereditary fructose intolerance, homocystinuria, tyrosinemia, and Wilson disease.11

The aim of the present study was to compare the demographic and anthropomteric measurements with and without NAFLD.

The prospective study was conducted at SGT Medical College, Hospital, and Research Institute over a period of 18 months, encompassing both outpatient and inpatient settings. Consecutive 50 newly diagnosed patients of hypothyroidism were included using convenient sampling, adhering to specific inclusion and exclusion criteria.

Inclusion and Exclusion Criteria

Inclusion criteria comprised individuals diagnosed with hypothyroidism aged over 18 years. Exclusion criteria included patients with Diabetes mellitus, alcohol intake exceeding 240 ml/day (8 units), acute fatty liver of pregnancy, and viral hepatitis.

Methodology

Participants provided informed consent and completed a structured questionnaire assessing symptoms such as weight gain, fatigue, constipation, cold intolerance, dry skin, hair changes, voice changes, and menstrual irregularities. Detailed histories, including past medical, personal, surgical, alcohol intake, and drug histories, were recorded. General physical examinations and systemic examinations were conducted.

Investigations

·         Liver Function Tests: Performed on a fully automated biochemical analyzer using the enzymatic method to assess SGOT and SGPT levels.

·         Viral Markers Detection: Conducted via enzyme immunoassay to detect HBsAg (for Hepatitis B), Anti-HCV (for hepatitis C), and HIV I & II antigens (for HIV).

·         Thyroid Profile: Evaluated using CLIA (Chemiluminescence immunoassay) to measure TSH, Free T3, and Free T4 levels during fasting.

·         Ultrasound Abdomen: Carried out to evaluate participants for Nonalcoholic Fatty Liver Disease (NAFLD).

Statistical Analysis: Initially, the proformas were reviewed for completeness, and any errors or missing values in the data were corrected. The cleaned data was then entered into Microsoft Excel, with a Master-chart prepared for reference. A licensed version of SPSS software, version 24.0 (Chicago, Illinois), was used to analyze the data. The findings were shown using tables, text, bar graphs, and pie charts after the first round of univariate analysis. Categorical variables were described by calculating their frequencies, and continuous variables were described by measures of central tendency and dispersion, both of which are components of descriptive statistics. In order to do bivariate analyses, we used the ANOVA test for quantitative variables and the Chi-square test or Fisher's Exact test for categorical variables. For statistical purposes, a p-value below 0.05 was deemed significant.

Table 1: Age distribution of study participants

The age distribution of the study participants had a mean age of 45.78 years, a median age of 45 years, a standard deviation of 13.9654 years, and ages ranging from a minimum of 22 years to a maximum of 80 years.

Table 2: Distribution of participants according to baseline characteristics

The age distribution of participants showed that 20 individuals (40.0%) were under 40 years old, 24 participants (48.0%) were between 41 and 60 years old, and 6 participants (12.0%) were over 60 years old, with a total of 50 participants (100.0%). The distribution of participants according to gender revealed that there were 29 females, making up 58.0% of the total, and 21 males, accounting for the remaining 42.0%, with a total of 50 participants (100.0%). Out of the total 50 participants, 31 (62.0%) followed a vegetarian diet, while 19 (38.0%) followed a mixed diet.

Table 3: Distribution of Anthropometric measurements among study participants

The distribution of anthropometric measurements among study participants showed that the mean weight was 77.06 kg, with a standard deviation of 8.41 kg, ranging from 58.00 kg to 92.00 kg. The mean height was 1.71 meters, with a standard deviation of 0.06 meters, ranging from 1.61 meters to 1.79 meters. The mean Body Mass Index (BMI) was 26.54, with a standard deviation of 3.40, and a range from 20.07 to 34.29. The median values for weight, height, and BMI were 79.00 kg, 1.70 meters, and 26.25, respectively.

Table 4: Comparison of age, gender and diet between the patients with and without NAFLD

Among the 19 patients without NAFLD, 42.1% were under 40 years old, 47.4% were aged between 41-60 years, and 10.5% were over 60 years old. In contrast, among the 31 patients with NAFLD, 38.7% were under 40 years old, 48.4% were aged between 41-60 years, and 12.9% were over 60 years old. Statistical analysis showed no significant difference in age distribution between patients with and without NAFLD, with a p-value of 0.955, indicating that age was not a differentiating factor in the presence of NAFLD among the study participants. Among the 19 patients without NAFLD, 57.9% were female and 42.1% were male. For the 31 patients with NAFLD, 58.1% were female and 41.9% were male. Statistical analysis revealed no significant difference in gender distribution between patients with and without NAFLD, with a p-value of 0.726. Among the 19 patients without NAFLD, 68.4% followed a vegetarian diet, while 31.6% had a mixed diet. In contrast, among the 31 patients with NAFLD, 58.1% followed a vegetarian diet and 41.9% had a mixed diet. The p-value associated with this comparison is 0.532, indicating no statistically significant difference in diet type between patients with and without NAFLD.

Table 6: Comparison of anthropometric measurements between the patients with and without NAFLD

Patients without NAFLD had a mean weight of 71.58 kg (standard deviation = 9.22), while those with NAFLD had a higher mean weight of 77.97 kg (standard deviation = 7.90). The difference in weight between the two groups was statistically significant (p = 0.001). Heights were similar between groups, with patients without NAFLD averaging 1.70 meters (standard deviation = 0.06) and those with NAFLD averaging 1.71 meters (standard deviation = 0.07, p = 0.609). However, BMI showed a significant difference, with patients without NAFLD having a lower mean BMI of 23.22 (standard deviation = 3.69) compared to those with NAFLD, who had a mean BMI of 26.73 (standard deviation = 3.26, p = 0.001).

The study population had a mean age of 45.78 years, with the majority of participants (48.0%) being in the 41-60 years age group. This age distribution is consistent with the findings reported in previous studies on the association between hypothyroidism and NAFLD. The study by Augustine et al13 had a mean age of 37.63 ± 7.66 years in their study population, which also included individuals with hypothyroidism and NAFLD. Similarly, the study by Elshinshawy et al12 had a similar age range, with participants with hypothyroidism and NAFLD being predominantly middle-aged.

The relatively older age profile of the current study population may be attributed to the fact that the participants were newly diagnosed with hypothyroidism, which is more common in the middle-aged and older population. The progression of NAFLD is also typically associated with increasing age, as the accumulation of risk factors and metabolic derangements over time can contribute to the development and progression of fatty liver disease. The study cohort had a higher proportion of female participants (58.0%) compared to males (42.0%). This gender distribution is also in line with the observations reported in previous studies on the relationship between hypothyroidism and NAFLD. The study by Augustine et al13 also had a predominance of female participants, with the study population being predominantly female. Similarly, the study by Elshinshawy et al12 included a higher proportion of female participants in both the hypothyroid and control groups. The higher prevalence of hypothyroidism and associated metabolic disorders, such as NAFLD, among women compared to men has been well-documented in the literature. This gender disparity can be attributed to various factors, including hormonal influences, genetic susceptibility, and differences in fat distribution and metabolic regulation between males and females.

The study participants had a mean body weight of 77.06 kg, a mean height of 1.71 meters, and a mean Body Mass Index (BMI) of 26.54. These anthropometric characteristics are consistent with the existing literature on the association between hypothyroidism and NAFLD. The study by Augustine et al13 reported a mean BMI of 25.07 ± 1.5 kg/m2 in their study population, which is slightly lower than the current study's findings. Similarly, the study by Elshinshawy et al12 found that participants with hypothyroidism had a significantly higher BMI compared to the control group. The higher BMI observed in the current study population is particularly relevant, as obesity and excess adiposity are well-established risk factors for the development and progression of NAFLD. The strong association between increased body weight, BMI, and NAFLD in hypothyroid patients has been consistently reported in the literature and is further corroborated by the findings of the current study.

The study participants were divided into two dietary groups, with 62.0% following a vegetarian diet and 38.0% following a mixed (vegetarian and non-vegetarian) diet. This dietary distribution is an important consideration in the context of NAFLD, as dietary factors can significantly influence the development and progression of fatty liver disease. While the current study did not find a statistically significant difference in the prevalence of NAFLD between the vegetarian and mixed diet groups, the potential impact of dietary patterns on NAFLD in hypothyroid patients remains an important factor to consider. Previous studies have explored the relationship between dietary habits and NAFLD, with some evidence suggesting that a plant-based, Mediterranean-style diet may have a protective effect against the development of fatty liver disease.14,15 However, the specific dietary considerations in the context of hypothyroidism and NAFLD require further investigation. The diversity of dietary patterns observed in the current study population reflects the real- world clinical setting and underscores the need to consider the potential influence of dietary factors when evaluating the management of NAFLD in hypothyroid patients.

The analysis did not find any statistically significant differences in the age and gender distributions between participants with and without NAFLD. This is in contrast to the general epidemiological trends observed in the general population, where advancing age and male gender are typically associated with an increased risk of NAFLD. The lack of a significant association between age, gender, and NAFLD in the current study population of hypothyroid patients suggests that the presence of underlying thyroid dysfunction may be a more dominant factor in the development of fatty liver disease, potentially overriding the typical demographic risk factors. The current study did not find a statistically significant difference in the prevalence of NAFLD between participants following a vegetarian diet and those following a mixed diet. This observation is in contrast to the existing literature, which has suggested that certain dietary patterns, such as a plant-based or Mediterranean-style diet, may have a protective effect against the development of NAFLD. The lack of a significant association between dietary habits and NAFLD in the current study population of hypothyroid patients may be influenced by the underlying thyroid dysfunction, which may be a more dominant factor in the development of fatty liver disease compared to dietary factors.

The current study investigated the prevalence of nonalcoholic fatty liver disease (NAFLD) and explored the association between various clinical factors with the presence of NAFLD in this population. Participants with NAFLD had significantly higher body weight, BMI.

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