Evaluation of the Abnormalities of Lipid Profile in Patients with Cholelithiasis

Objective: Cholelithiasis is a chronic recurrent illness that affects the hepatobiliary system. Gall stone formation is caused by the impaired metabolism of cholesterol, bile acids and bilirubin. of case group 26(48.1%) had serum HDL-C levels between 35-45 mg/dl as compared to the controls 8(14.8%) with a statistically significant difference between them (p=0.001). Moreover, higher serum TGs levels > 200 mg/dl observed in 1(1.9%) patients in case group and 7 (13.0%) in controls with statistically significant difference between them (p=0.006) Conclusion: This study concluded that the significant association observed between gallstones and abnormal lipid levels among controls and cases. Therefore, it was depicted that the risk of cholelithiasis increased with discrepancies in lipid profiles.

of case group 26(48.1%) had serum HDL-C levels between 35-45 mg/dl as compared to the controls 8(14.8%) with a statistically significant difference between them (p=0.001). Moreover, higher serum TGs levels > 200 mg/dl observed in 1(1.9%) patients in case group and 7 (13.0%) in controls with statistically significant difference between them (p=0.006) Conclusion: This study concluded that the significant association observed between gallstones and abnormal lipid levels among controls and cases. Therefore, it was depicted that the risk of cholelithiasis increased with discrepancies in lipid profiles.

INTRODUCTION
Gallstone disease (GSD) is a frequently observed disease of the gastrointestinal tract with10%-15% occurrencerate and a frequency of 1.4% annually in the adult populace of developed nations [1,2].Gallstones are categorized into three major types: pigment, cholesterol, and mixed gallstones. Cholesterol gallstones are composed of 51%-99% of pure cholesterol. Mixed gallstones contain cholesterol in addition to bile acids, calcium salts, phospholipids and bile pigments. Approximately 70-80% cases have mixed gallstones [3]. In addition to, about 75%-80% of cases in Western countries contain cholesterol gallstones [4].
It is evidently stated that multiple risk factors are involved in the development of GSD [5] that are aging, gender, nutritional status, low fiber ingestion, high calorie intake, highly refined carbohydrates, raised level of triglycerides in blood, physical immobility, pregnancy, parity, heaviness and obesity [6,7]. Additionally, it was predicted by one research that in generalincidence of gallstone in patients was about 2.4%. The possibility of gallstone formation was 2.60 folds greater in 45 years and above 45 years of age people [8]. It is stated that females indicated highincidence of asymptomatic cholelithiasis in age < 40 years as compared to males (2.7% against 1.9%) [9]. A mnemonic for remembering the risk factors related to gallstones is female, fat, fertile and forty. Furthermore, those femalesare more prone to develop gallstones that intake oral contraceptive pills, multiparous women having 3 or more children or experienced full term pregnancies [10].
The process of gall stone formation involves complex mechanism. Most important factors that direct the stone formation includes concentration of secreted bile within the gall bladder, Nucleation of triglyceride crystals, and incomplete emptying of gall bladder [11]. Most fundamental factor in the formation of gallstone is increase concentration of cholesterol in the bile which is insoluble in water and secreted from the canalicular membrane in unilamellar phospholipid vesicle. Bile salts and phospholipids, mainly phosphatidyl choline in the bile are essential for the cholesterol solubility [12]. Excessive cholesterol or decreased phospholipids and/or bile acid leads to form multi lamellar vesicles resulting a nucleation of the cholesterol crystals that causes stone formation. The secretion of cholesterol supersaturated bile promoting a formation of stone by reducing phospholipids, gallbladder immobility, deferred transit times of large intestine that supports the re-absorption of deoxy-cholic acid and the ileum resection (lessen the acid pool), have all been connected in the gallstone formation [13].
Generally, hyperlipidemia is recognized by high serum total cholesterol (TC), low level of highdensity lipoprotein cholesterol (HDL-C), serum triglycerides (TGs), low-density lipoprotein cholesterol LDL-C, and very low-density lipoprotein cholesterol (VLDL-C). It is thought to be controversial that lipid abnormalities are related to cholelithiasis. Few researches revealed a existence of significant association between hyperlipidemias and gallstones particularly in an increased LDL-C and triglyceride levels [14,15] whereas some studies reported an insignificant association between hyperlipidemias and cholelithiasis [1,16,17].
It is believed that conflicting data exists regarding association of cholesterol serum levels, triglycerides, being overweight, serum glucose levels and nutritional status with gallstone. One research demonstrated that raised TG levels, duration of obesity, reduce physical exercise can cause gallstone diseases [18]. Similarly, one research demonstrated that vegetables and fruits consumption reduce the probability of formation of gallstone on the other hand, ingestion of fried and spicy foods significantly enhance the chances of gallstone formation [5]. In contrast to some studies, a non-vegetarian or vegetarian diet, fruit consumption, lack of physical activity, HDL cholesterol, triglyceride levels and body mass index were not recognized as a remarkable cause for the occurrence of gallstone formation [19].Multiple factors are involved in between formation of gallstone and blood cholesterol levels. Despite the fact that the function of blood cholesterol levels in the progression of symptomatic GSD is still not well recognized. It was evidently proved by meta-analysis studies and systemic review that vegetarian diets efficiently lowers the concentration of total cholesterol (TCH), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in blood [20][21][22].
There is a scarcity of literature in Pakistan regarding incidence of gallstones and its association with blood cholesterol level. Since the evaluation of risk factors can assist in directing remedial and preventive approaches.Therefore, the aim of this study was to compare the lipid abnormalities in the patients presenting with gallstones with the controls.

METHODOLOGY
This was a Case control study conducted in surgical department of Sindh Government Hospital Korangi 5 after taking approval from Ethical review committee of Hospital, by using convenient sampling technique. The duration of the study was about 06 months. A total of 54 patients aged above 15 years of both the genders wherein 28 patients with Gallstone disease that were diagnosed by ultrasound as moveable echoes in the gallbladder with acoustic shadows were considered as case group and 29 patients with no history of gallstones were recruited as control group admitted through surgical OPD, Emergency or referred from other OPDs were included in the study whereas patients with acalculous gallbladder disease on ultrasound, terminal ileal resection, known severe coronary artery disease, hemolytic diseases (hereditary spherocytosis, sickle cell anemia on history and CBC film), liver cirrhosis (on abdominal ultrasound) and patients on antihyperlipidemic or hypolipidemic drugs were excluded from the study.
After receiving written consent from every patient, blood samples were drawn from the cases and controls that were analyzed for serum TGs, TC, and LDL-C and HDL-C levels. Gallstone was identified on Trans-abdominal ultrasound 3.5 mHz in a fasting status. Proforma is used to record all the findings. Fasting lipid profile was measured following all night fasting in hospital laboratory by using CHOP PAP for cholesterol and Triglyceride along with lipid clearing factor for HDL-C, VDL-C and VLDL-C by same technologist.
Data was entered and statistically analyzed by using SPSS software, version 20. Ages of cases and controls were expressed as mean with standard deviation. Demographic characteristics such as age, gender and Continuous variables such as lipid parameters (TC, HDL-C, TGs, LDL-C), and VLDL-C) were documented as frequencies and percentages. Student's t-test was used to compare the data between the cases and the control groups. P value less than 0.05 was considered as statistically significant.

RESULTS
A total of 54 patients were recruited in the study, out of which 28 were cases and 27 were controls. The mean age of the patients was 35.49 years and that of controls was 34.56 years. In the study, 44(81.5%) were females and 10(18.5%) were males. Most of the patients 23(42.6%) were had aged 25-35 years and 19(35.2%) were had aged 35-45 years, as shown in Table 1.
Lipid profile of the cases and controls revealed that serum LDL-C was significantly higher (p=0.014) in control group 17(31.5%) as compared to cases 8(14.8%). The study evinced that the most of the patients of case group 26(48.1%) had serum HDL-C levels between 35-45 mg/dl as compared to the controls 8(14.8%) with a statistically significant difference between them (p=0.001). Furthermore, it was observed that serum VLDL-C were high in the case group 21(38.9%) as compared to the controls 17(31.5%) but the comparison was not statistically significant (p=0.186). Additionally, TC levels were high in 12(22.2%) patients in case group and 18(33.3%) in controls but with a

DISCUSSION
Gallstone diseases is a chronic recurrent disease that affects the hepatobiliary system characterized by the impaired cholesterol, bilirubin and bile acids metabolism resulting a gallstones formation in the hepatic bile duct, common bile duct, or within the gallbladder [23]. This study demonstrated the lipid abnormalities caused by the presence of gall stones.
One cross-sectional prospective analysis compared the abnormalities in gall stone patients with controls. In their study, mean age of the patients was reported 40.90 years and that of controls was 34.74 years. There was statistically insignificant difference was observed in higher serum TC levels between cases and controls. On the other hand, higher serum TGs levels were observed in the patients than the controls with a statistically significant difference between them. Furthermore, lower levels of serum HDL-C and LDL-C were found in cases as compared to the controls with a statistically significant association between them [24]. The present study was in accordance with the above mentioned research and revealed that the mean age of cases was reported 35.49 years and that of control was 34.56 years. Concerning lipid abnormalities, it was revealed that serum TC levels were statistically insignificant in the gallstones patients as compared to the control group. (p=0.085). TGs levels were significantly raised in controls as compared to the case group. (p=0.006). Furthermore, serum HDL-C levels were significantly low in the case group as compared to the control group.(p=0.001). On the other hand, LDL-C level was significantly higher in controls than cases (p=0.014).
One of the studies compared the effects of gall stones on lipid parameters wherein the mean age of the patients was reported 40.90 ± 12.65 years. Most of the patients around 92% were female [24]. Comparable findings were observed in the researches performed by Weerakoon HT et al. [17] and Gul H et al. [25] with the reported mean ages of 44.6 ± 10.4 years and 43.18 ± 13.970 years, correspondingly. Furthermore, researches conducted by Weerakoon HT et al. [17], Gul H et al. [25] and Halgaonkar P et al. [26] also indicated that the mostly patients were female revealing significant role of hormone in disease process of gallstones formation. The present study was not in accordance with the above reported studies and revealed that the study subjects had mean age 35.49 years in cases and 34.56 years in controls with female preponderance.
Similarly, one research by Al-Saadi N et al. [27] demonstrated that significant elevation of serum cholesterol levels in the gallstones patients than the control group. Even though, the supersaturation of bile with cholesterol has distinct role in disease process of gallstones but their relationship of gallstones with higher level of serum cholesterol in patients is debatable in literature that can be broadly elucidated by many factors like genetics, geological, social and nutritional status in causing different kind of gallstones. [27] In contrast to the above findings, the present study revealed that serum cholesterol levels was statistically insignificant in the gallstones patients as compared to the control group. (p=0.085).
Another retrospective study compared the serum lipid abnormalities in 133 females who have gall stones with control group. Their study showed that serum LDL level was statistically significant in females over 40 years of age (p<0.05), while they did not show significant association with other parameters [1]. The present study endorsed the above cited research as LDL-C level was significantly raised in controls than cases. On the other hand, our study showed inconsistency in a manner as statistically significant difference observed in TGs levels (p=0.006) and HDL levels (p=0.001) of cases and controls.
Furthermore, one more research broadly assessed the association between lipid profile (TC, LDL-C, HDL-C, and TGs) and probable factors of GSD [28]. This meta-analysis revealed that TGs was positively associated with GSD vulnerability. These findings showed similarity with another cohort trail [29]. Our study was consistent with the above cited study and proved that there was statistically significant difference observed between TGs levels of cases and controls (p=0.006).
Similarly, one more research focused to elaborate the preponderance of gall stones in females. They observed that out of 526 patients, 384 were female and 142 were male showing females predilection over males. This is due to the presence of sex hormone like estrogen that is the principal sex hormone in female. This hormone regulates both health and disease process by binding to numerous receptor [30]. It was also evidently supported that high frequency of GD was seen in females as compared to the males, particularly in the pre-menopausal stage due to hormonal changes [30]. Similar findings were shown by previous Pakistani study [31]. Our study was in agreement with the above researches and revealed that out of 54, 44 patients were female indicating females predilection over males. Therefore, it can be assessed that physical inactivity, female, older age and marital status has a significant role in pathogenesis of GSD. However, additional prospective researches must be performed in order to recognize the cause of disease. Furthermore, more investigations and researches must be conducted to demonstrate the recent recognized demographic and biochemical factors responsible for GD prevalence that can help to find out proper remedial alternatives rather than surgical management. This study has some limitations as it used small study sample so it is needed to collect data from larger sample to explore more outcomes of disease. \

CONCLUSION
This study concluded that the significant association observed between gallstones and abnormal lipid levels among controls and cases. Low levels of high density lipoprotein were statistically significant in the cases as compared to the control group. Furthermore, triglyceride levels and low density lipoprotein levels were significantly raised in the control group as compared to cases. Therefore, it was depicted that the risk of cholelithiasis increased with discrepancies in lipid profiles.

ETHICAL APPROVAL
As per international standard or university standard written ethical approval has been collected and preserved by the author(s).

CONSENT
As per international standard or university standard, patients' written consent has been collected and preserved by the author(s).