Prevalence of Gall Stone Disease and its Relation to Hypercholesteraemia, Hypertension and Diabetes in Affluent

North Indians: Population Based Study

over 50,000 cholecystectomies are performed each year [3].The prevalence of gallstones increases with age in all racialgroups; increased body weight, rapid weight loss, pregnancy,alcoholic cirrhosis, and a family history of gallstone diseasealso appear to be risk factors [4,6]. Studies done in India seemto show a lower incidence of gall stones [7]. In a studycomprising of a total of 1104 subjects examined, 48 (4.3%)were found to have gallbladder stones8. This prevalence isabout half of that in the western world. However India being a

39 Apollo Medicine, Vol.1 September 2004

GALL stones are one of the most common disorders of thegastrointestinal tract, affecting about 10% of people in westernsociety[1]. Gall stone disease constitutes a major healthproblem in the United Kingdom and the United States [2,3].

Gall stones are the most common abdominal reason foradmission to hospital in developed countries and account foran important part of healthcare expenditure [2,3]. Around 5.5million people have gall stones in the United Kingdom, and

Original Article

PREVALENCE OF GALL STONE DISEASE AND ITS RELATION TO HYPERCHOLESTERAEMIA,HYPERTENSION AND DIABETES IN AFFLUENT NORTH INDIANS: POPULATION BASED STUDY

Arun Prasad+, Tarun Sahni*, Ashima Lyall, Sindhu Chandra+ and Praveen GoenkaFrom the Apollo Surgical Sciences Centre+, Department of Internal Medicine*,

Indraprastha Apollo Hospitals, New Delhi - 110044, India.Correspondence to: Dr. Arun Prasad, Apollo Surgical Sciences Centre,

Indraprastha Apollo Hospitals, New Delhi 110044, India.E-mail: laparoscopy@hotmail.com

Objective: To investigate the prevalence of gall stone disease in the affluent north Indian population and to study itsassociation with hypercholesteraemia, hypertension and diabetes, in isolation and together.Design: A survey of1000 subjects who reported to the hospital for routine health check (including physical examination, routine bloodinvestigations and abdominal ultrasound).Setting : Apollo Hospital, a private corporate hospital at New Delhi, India.Subjects: 1000 subjects randomly selected, all above 20 yrs. of age; belonging to the higher socio-economic statusin urban north India.Results: We observed the prevalence of gall stones in our selected group to be 12% (n = 120).Of the 1000 people we studied, the percentage of gall stones in women (17.63%) was found to be significantly higherthan that of men (9.02%) of any age group. Age in itself was found to be statistically significant for the presence of gallbladder stones with a definite increasing trend in the prevalence of stones with increasing age (24.1% in 70-80 yrs.).On differential studies in each gender, this significance was found to be relatively greater in males. Serumcholesterol levels were however not found to be statistically significant in the prevalence of gall bladder stones in ourstudy (p = 0.423). However, when differential analysis was performed in each gender, we found serum cholesterol tobe relatively more significant in males (p = 0.458) than females (p = 0.947). There was a positive co-relation(Pearson’s correlate R = 0.115) between the prevalence of diabetes and gall stones that we observed in our data.This co-relation was observed to be even greater in males (p = 0.005) with diabetes in comparison to thecorresponding females (p = 0.028). We found a higher percentage of people with co-morbid hypertension and gallbladder stone pathology (17.32%). The differential studies in each sex showed a much higher significance value formales (p = 0.022) over females (p = 0.082) with co-existing hypertension. The multi-variate analysis done for thesame study group also revealed that raised serum cholesterol levels, though non-significant statistically on theirown, were significant when co-existing with diabetes (p = 0.018). The other co-existing factors found to bestatistically significant were diabetes with increasing age (p = 0.015); co-morbid diabetes, hypertension andhypercholesteraemia (p = 0.007); and diabetes with hypertension as well as hypercholesteraemia in the setting ofincreasing age(p = 0.001).Conclusion: Gall stone disease is one of the important lifestyle related diseases of todayas observed by its high prevalence rate in our study, comparable to the rates in the western world[1,2]; with therebeing strong co-relations between the prevalence of gall stones and the other lifestyle diseases like diabetes,hypertension and hypercholesteraEpidemiological implications :• Studies from developing countries are not clear regarding the association between the total serum cholesterol

and prevalence of gall stone disease [2,15] .• In urban north India, the prevalence of hypercholeateraemia and hypertension is high.• The prevalence of gall stone disease is higher among the people with hypertension or diabetes or with co-morbid

hypercholesteraemia with hypertension.Key words: Gall stone disease, Hypertension, Diabetes.

Original Article

Apollo Medicine, Vol. 1, September 2004 40

diverse country, taking an overall average may not reflect trueprevalence in the population that consists of diverse ethnicgroups, variation in dietary habits that vary depending uponsocio-economic status [9].

Methods

One thousand people coming for health check up to ApolloHospital, New Delhi, India from 1st January 2003 onwardswere selected for the study. Physical examination includedmeasurements of blood pressure. Supine blood pressure wasmeasured with a standard mercury manometer. Two readingsfive minutes apart were taken as per WHO guidelines [10].When a high blood pressure (>= 140/90 mm Hg) was noted athird reading was taken after 30 minutes. The lowest of thethree readings was recorded and hypertension diagnosedwhen systolic blood pressure was >= 140mm Hg or diastolicblood pressure was >= 90 mm Hg [11-13]. The prevalence ofgall stones in the population was measured conveniently byultrasonography [4,6] and the prevalence of gallbladderdisease was taken as the sum of people with gall stones andthose who had a cholecystectomy in the past. A fasting bloodsample was obtained from all the subjects and diabetes wasconsidered in patients with fasting venous plasma glucoseover 7 mmol/dL (126 mg/dL) or known diabetics undertreatment. The total cholesterol concen-trations wereestimated by an enzymatic method and hypercholesterolemiawas taken as level above 5 mmol/dL (193 mg/dL or above)[9,10]. The above data were collected and a statistical analysiswas done.

Statistical analysis

Data were pooled and computerized. Prevalence rates aregiven as percentages. To determine the significance of trendsin the prevalence of gall stone disease and risk factors the χ2

test was used. The Mantel- Haenzel statistic which tests forlinear association was determined with the SPSS statisticalpackage (SPSS Inc, Chicago). In addition, Pearson’scoefficient of rank correlation (R) was calculated for gall stonestatus with various characteristics (age, sex, blood pressure,cholesterol levels and plasma glucose levels). Multivariateanalysis to determine the overall relation of gall stone diseasewith factors such as hypercholesteraemia, diabetes andhypertension present in various combinations was performedby logistic regression. The independent variables werepresence or absence of hypertension, diabetes andhypercholesterolaemia. The dependent variable was the gallstone status. A relation was initially determined between therisk factors and the gall stone status in any sex and age group.Gender, which is the major confounding factor, was thenaccounted for by performing differential studies in males andfemales and obtaining χ2 values separately for the samecharacteristics (P values are two tailed, and significance wastaken as =< 0.05).

Results

Gall Stone Prevalence

Out of a 1000 people studied, gall stones were present in120 people ( 12% ). These are people with ultrasound findingsof gall bladder calculi or as post cholecystectomy status.

Age

The age wise prevalence is as seen below (Table 1 &Fig. 1). The maximum incidence of gall stones was in the agegroup 70-80 yrs = 24.1%

Sex Distribution

There were 346 females and 654 males in the populationstudied. Of these, 61 and 59 respectively had gall stones(Fig. 2). 17.6% of the females and 9% of males had gall stones.

TABLE 1. Age wise prevalence of Gall stone.

Age Number Total Percentage

10-20 0 15 020-30 4 93 4.330-40 15 224 6.740-50 36 291 12.450-60 43 233 18.560-70 15 113 13.370-80 7 29 24.180-90 0 2 0

Total 120 1000 12

Fig. 2. Sex-wise prevalence.

4 15 36 43 15 7

93

224

291233

113

2915 2

050

100150200250300350

10-20 20-30 30-40 40-50 50-60 60-70 70-80 80-90

AGE GROUPS

TOTALGALL STONES

Fig. 1. Age-wise prevalence.

59 61

654

346

0100200300400500600700

Males Females

41 Apollo Medicine, Vol. 1, September 2004

Original Article

TABLE 2. Prevalence of hypertension, diabetes &hypercholesteraemia.

Parameter Normal Abnormal

Blood pressure 746 254Blood sugar 865 135Serum cholesterol 474 526

Fig. 3. Prevalence of hypertension, diabetes and hyper-cholesteraemia

TABLE 3. The Association of Gall stones with various factors.

Variable Total N With GS R χ2 Odds Ratio (Confidence Intervals) P value

HT 254 44 0.096 8.464 1.847 (1.235 –2.762) 0.003DM 135 29 0.115 12.25 2.327 (1.462 –3.703) < 0.001HYPERCHOL. 526 59 –.025 0.497 0.885 (0.584 –1.253) 0.422HT + DM 56 12 - - 1.238 (0.476 –3.218) 0.661HT + HYPERCHOL. 147 20 - - 0.889 (0.439 –1.802) 0.744DM+ HYPERCHOL. 76 16 - - 2.037 (1.129 –3.676) 0.018HT + DM+ HYPERCHOL. 29 3 - - 0.533 (0.339 –0.839) 0.007

† p values calculated using Mantel-Haenzel’s χ2 test and multivariate logistic regression.‡ significant when p< 0.05( confidence limits of 95%); highly significant when p< 0.01 (confidence limits of 99%).∈ R - Coefficient of co-relation using Pearson's co-relation.

Hypertension, Diabetes & Hypercholesteraemia

The prevalence of hypertension ( defined as systolic BP>140 and/or diastolic BP >90 ), diabetes ( defined as plasmavenous glucose level >7 m mol/dL or >192.8 mg/dL) andhypercholesterolemia ( defined as total serum cholesterol>5 m mol/dL) was as follows ( Table 2 & Fig. 3).

The distribution of hypertension, serum cholesterol andblood sugar was compared in those with gall stones versusthose without gall stones (Fig. 4). We found the followingfigures:

Percentage of hypertensives in those without gall stones =23.9%Percentage of hypertensives in those with gall stones =36.7%Percentage of hypercholesteraemics in those without gallbladder stones = 53.1%Percentage of hypercholesteraemics in those with gall bladderstones = 49.2%Percentage of diabetics in those without gall stones = 12%Percentage of diabetics amongst those with gall stones =24.2%

Statistical analysis was done with this data in respect to theassociation of gall stones with the above mentioned factors(Table 3). Further analysis was done for males and females(Table 4).

Discussion

The prevalence of gall stones in any population isdependent on a number of factors including the ethnicity,demography and various lifestyle factors.

In India, a gallstones survey limited to railroad workersconducted in 1966 utilizing oral cholecystography had

Fig. 4. Distribution of hyperension, hypercholestaemia anddiabetes

86.5

47.4

74.6

25.413.5

52.6

0

20

40

60

80

100

BP Sugar Cholesterol

normal valuesraised values

23.9

36.7

53.1 49.2

12

24.2

0

10

20

30

40

50

60

Hypertension Cholesterol Diabetes

No Stones Stones

Original Article

Apollo Medicine, Vol. 1, September 2004 42

suggested that gallbladder stones occurred 7 times morecommonly in North Indian workers than in South Indianworkers. This difference was attributed to the different ethnicbackground of the workers [16]. Another community studywas performed to assess the prevalence of gall bladder stonesin 1989 in four different colonies of Delhi, each withinhabitants belonging to a specific ethnic group. Of a total of1104 subjects examined, 48 (4.3%) were found to havegallbladder stones15 with an incidence of 15% in the NorthIndian Punjabi community, of 24% in the Bengali communityand 4% in the South Indian community.

We undertook this study at the Apollo Hospital, New Delhi(a private corporate hospital) in a random group of 1000people reporting to the hospital for their Annual HealthChecks. These people were assessed for the presence of stonesin the gall bladder or for post cholecystectomy status on theultrasound. We observed the prevalence of gall stones in ourselected group to be 12%. This was significantly larger thanwhat was observed in a previous study. This could be due to thefact that patients reporting to this hospital belonged to thehigher socio-economic status.

Gender was found to be an important influence in theprevalence of gall bladder stones. Of the 1000 people westudied, the percentage of gall stones in women(17.32%) wasfound to be significantly higher than that of men(9.1%) of anyage group. (The Pearson’s coefficient of co-relation for thepresence of gall stones in women was of the order of 0.126 thathad a significance value by Pearson’s X2 <0.001). Age in itselfwas found to be statistically significant for the presence of gallbladder stones with a definite increasing trend in theprevalence of stones with increasing age (R = 0.140; p<0.001). On differential studies in each gender, thissignificance was found to be relatively greater in males(p = 0.014) than in females(p = 0.036).

The study group was analysed for the presence ofhypercholesteraemia with normal levels taken up to an uppervalue of 192.8 mg/dL (5 mmol/dL ) Serum cholesterol levelswere however not found to be statistically significant in theprevalence of gall bladder stones in our study(p = 0.423). This

observation may be influenced by the fact that the prevalenceof hypercholesteraemia was as high as 52.6% reflecting on thehigher socio-economic bias of our study group. However,when differential analysis was performed in each gender, wefound serum cholesterol to be relatively more significant inmales (p = 0.458) than females (p = 0.947).

The same group was assessed for fasting serum glucoselevels with a lower limit of 126 mg/dL of fasting blood sugartaken as the cut off for diabetes or the positive history ofmedications for diabetes mellitus obtained for the same. Therewas a positive co-relation between the prevalence of diabetesand gall stones that we observed in our data(r = 0.115). Thisco-relation was observed to be even greater in males(p = 0.005) with diabetes in comparison to the correspondingfemales(p = 0.028).

Individuals were also assessed for the presence ofhypertension that included those with history of hypertensionon anti-hypertensives, those with blood pressure valuesgreater than 140/ 90 as well as those with isolated systolichypertension of >150 systolic pressure. We found a higherpercentage of people with co-morbid hypertension and gallbladder stone pathology (21.5%). The differential studies ineach sex showed a much higher significance value for males(p = 0.022) over females (p = 0.082) with co-existinghypertension.

The multi-variate analysis done for the same study groupalso revealed that raised serum cholesterol levels, though non-significant statistically on their own, were significant when co-existing with diabetes (p = 0.018). The other co-existingfactors found to be statistically significant were diabetes withincreasing age (p = 0.015); hypercholesteraemia with diabeteswith hypertension(p = 0.007) on their own and in the settingof increasing age(p = 0.001).

ConclusionGall stone disease constitute a major portion of digestive

tract disorders world over. We in our study have found theincidence amongst the urban affluent of North India to be morethan the overall incidence reported in USA and WesternEurope.

TABLE 4. Differential Studies in Each Gender

Variable Male Female

No. With stones χ2 p No. With stones χ2 p

Cholesterol 346 28 ( 8.1%) 0.550 0.458 180 31 (17.2%) 0.004 0.947Daibetes 93 16 ( 17.2%) 7.709 0.005 42 13 (31%) 4.831 0.028Hypertension 168 23 ( 13.7%) 5.256 0.022 86 21 (24.4%) 3.028 0.082

† χ2 calculated using Mantel Haenzel's test.‡ p value significant when p <0.05 .

43 Apollo Medicine, Vol. 1, September 2004

Original Article

This may be related to the life style and dietary habitsamongst this selected population which is quite different fromthe rest of the country.

In this study we have found strong co-relations betweenthe prevalence of gall stones and the various lifestyle diseaseslike diabetes, hypertension and hypercholesteraemia. Hence,in view of our observations, we propose to considercholelithiasis also as an important part of the lifestyle relateddiseases of today.

ACKNOWLEDGEMENTS

We would like to thank the Departments of Radiology andClinical Pathology, Apollo Hospital, New Delhi for sharingand contributing data for this study.

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