Lactose tolerance in a jewish population

In order to investigate the possible effect of environment on lactose deficiency, lactose tolerance tests were performed on 32 healthy Jewish adults living in Western Canada. The results were compared with those obtained in Jewish communities in Israel. There were 20 males and 12 females, 20–47 years of age, with a mean of 27.2 years. The tests revealed that 22 (68.8%) of the subjects were lactose intolerant on the basis of a maximal blood glucose rise of less than 20 mg/100 ml above the fasting level after the lactose load. The mean maximum blood glucose rise was 4.1 mg/100 ml in the 22 lactose-intolerant subjects and 33.6 mg/100 ml in the 10 lactose-tolerant subjects. Gastrointestinal symptoms during the test were observed in 95.5% of the subjects with a low rise in blood glucose, and in 10% of those with a normal rise in blood glucose. There was no relationship between lactose tolerance and milk intake. The results suggest a high incidence of lactose intolerance among North American Jews, and are similar to findings in Jewish communities in Israel.Supported by Grant A6249, National Research Council of Canada.The author wishes to thank Dr. M. Lee for his helpful comments; and Dr. J. A. Birkbeck and Mrs. Karen M. Ulveteg for their assistance with the lactose tolerance test.     

Lactose intolerance in Canadian West Coast Indians

Lactose tolerance tests were performed on 30 healthy Canadian West Coast Indians and 16 non-Indians of Northern European extraction. Among the Indians, there were 7 males and 23 females, aged 14–24 years, with only 1 above 20 years of age (mean 15.8 years). The non-Indians consisted of 3 males and 13 females, aged 15–26 years, with only 2 above 18 years of age (mean 17.4 years). The tests revealed that of the 30 Indians, 19 (63.3%) were lactose intolerant on the basis of maximal blood glucose rise of less than 20 mg/100 ml above the fasting level after the lactose load. Gastrointestinal symptoms during or after the test were observed in 68.4% of the subjects with a flat blood glucose curve and in 18.2% of those with normal curves. In contrast, of the 16 non-Indians, only 1 (6.3%) was lactose intolerant, and none experienced abdominal discomfort during or after the test. Milk consumption among most of the Indian subjects seems to be low by North American standards, as judged by their past milk-drinking habits. The results suggest a high incidence of lactose intolerance among West Coast Indians during adolescence.Supported by National Health Grant 609-7-236 and NRC Grant A6249, Canada.The authors wish to thank Father T. Lobsinger and the students at the Cariboo Student Residence, Williams Lake, British Columbia for their cooperation; and Dr. J. A. Birkbeck and Miss Ilse Borgen for their assistance.     

A standardized milk tolerance test

Inability to hydrolyze lactose does not always cause symptoms. The lactose tolerance test commonly used in diagnosis pinpoints the biochemical anomaly but does not establish whether it causes a functional disability. I therefore compared a milk tolerance test (500 ml milk) with the standard lactose tolerance test in 40 healthy adult volunteers for rise in blood sugar. A maximum glucose rise of 9 mg/100 ml or less indicated lactose malabsorption. Only one subject was misclassified by the milk tolerance test when compared with the lactose tolerance test (specificity 91.7%; sensitivity 100%). The test not only reproduces the worst symptoms that the subject is likely to suffer due to usual milk intake, but also accurately identifies the lactose malabsorber, thus yielding more information than the standard lactose tolerance test.     

Changes in plasma free fatty acid concentration following oral lactose tolerance tests as a test for lactose absorption in infants and children

Changes in blood glucose and plasma free fatty acid (FFA) following oral lactose tolerance tests (LTT) were measured in three groups of children. In three out of seventeen infants with secondary lactose intolerance, only a small increase (less than 25 mg/100 ml) in glucose was found, but a normal decline (more than 50% of fasting value) in FFA concentration occurred. Resumption of milk feeding proved that they were not intolerant to lactose. Six infants (37%) without lactose intolerance who were on a normal lactose-containing diet showed only small increases in glucose; five of them showed a normal decline in plasma FFA. Nine out of thirteen children with no symptoms following oral LTT failed to show an increase in blood glucose, while in only one there was a decline of less than 50% in FFA concentration. Our results suggest that measurement of plasma FFA following oral LTT may be a more reliable test for cleavage and absorption of lactose than LTT alone, but for the final evaluation of this test a study of larger groups is obviously needed.     

Use of the lactose-ethanol tolerance test in diabetes.

The standard lactose tolerance test involves measuring a patient's blood glucose after the ingestion of lactose. If the patient has lactase deficiency and is unable to hydrolyze lactose and absorb its monosaccharides, glucose and galactose, the blood glucose does not usually increase greater than 20 mg/100 ml. Since factors other than the absorption of glucose can cause an increase in the blood glucose of greater than 20 mg/100 ml in a diabetic, this test could be unreliable when it is performed on a diabetic. The present study was performed to determine whether the lactose-ethanol tolerance test could be used to diagnose lactoase deficiency in diabetics. This test involves measuring the blood galactase level, instead of the blood glucose, and the administration of ethyl alcohol to a subject prior to the test to delay the clearance of galactose from the circulation. The results indicate that the standard lactose tolerance test in which the blood glucose is measured is unreliable when performed on insulin-dependent diabetics, but that it can be reliable when performed on non-insulin-dependent diabetics. The lactose-ethanol tolerance test gave results in each type of diabetic which were qualitatively similar to those of nondiabetics. It was concluded that the latter test is a useful screening test for lactase deficiency in diabetics.     

Studies in the diabetic mutant mouse: V. Glucose tolerance in mice homozygous and heterozygous for the diabetes (db) gene

Summary Mice homozygous and heterozygous for the diabetes (db) gene were studied to determine: 1. whether latent carbohydrate intolerance is present in young normoglycemic diabetic mutants (db/db); 2. whether normoglycemic food restricted diabetic mutants are carbohydrate intolerant; and 3. whether mice heterozygous for thedb gene (db/+) manifest abnormalities in glucose tolerance, serum IRI levels or body weights. Blood glucose levels were determined 0, 1/2, 1, 2 and 3 h following intraperitoneal administration of 2 mg glucose/g body weight. Normals (+/+) and diabetics (db/db) showed similar glucose tolerance curves during the first two weeks of life; however, both were markedly glucose intolerant compared to normal adult mice. At 3 weeks a small number of mutants had higher 3 h levels than any achieved in normal mice. By 4 weeks the average value for diabetics prior to glucose loading (0 time) was significantly (P < 0.02) elevated (db/db — 144 mg glucose/100 ml, +/+ = 124 mg glucose/100 ml). Although food restriction reduced blood glucose concentration at 0 time, persistence of carbohydrate intolerance was readily demonstrable following glucose loading. — Abnormalities in heterozygotes (db/+), 3 to 16 months of age, were primarily restricted to male mice, which showed moderate, but statistically significant elevations in blood glucose both at 0 time and following glucose administration. Forty percent of male heterozygotes had higher serum IRI levels than any observed in normal control males. Body weights of male heterozygotes were significantly greater (P<0.01) than those in agematched normals.USPHS Research Career Development Awardee, Grant K4-AM-7394.     

Control of blood glucose levels in the streptozotocin diabetic rat using a long-acting heat-treated insulin

Summary Diurnal plasma glucose levels have been studied two hourly in streptozotocin diabetic rats during insulin treatment. Protamine Zinc Insulin induced a very steep fall in plasma glucose level from 359±100 (SD) mg/100 ml to 91± 49 mg/100 ml within two hours. Plasma glucose was then low (13–60 mg/100 ml) until after 18 hours when an equally steep rise in glucose concentration ocurred. Six other insulin preparations and several insulin treatment regimens were tested with the aim of normalising the 24 hour plasma glucose profile of streptozotocin diabetic rats. One preparation, a non-commercial, very long acting Ultralente NOVO (Mc, ox pH 5.5) yielded a diurnal plasma glucose profile reasonably close to normal when it was administered once a day and when the dose was based on daily blood glucose measurements. Mean plasma glucose was 122±55 mg/100 ml with a nadir of 55±15 and a maximal of 187±99 mg/100 ml.     

Failure of indomethacin to affect arginine-induced C-peptide and glucagon release in insulin-treated diabetics

Summary Fourteen insulin-treated diabetics were submitted to an arginine infusion test performed with either 11.7 or 5.85mg kg^-1 min^-1 arginine monohydrochloride infused during 40 min with or without previous oral administration of a low (75+50 mg) or a high (75 mg + 3 mg/kg) dose of indomethacin. Blood glucose, plasma non-esterified fatty acids, insulin, C-peptide and glucagon were determined at regular intervals before, during and after the arginine infusion. These parameters were totally unaffected by the two doses of indomethacin both in the basal state and during the arginine infusions at the two loads tested. Eight subjects had a basal C-peptide level above 0.07 pmol/ml and a mean (± SEM) maximal rise of 0.21±0.04 pmol/ml during the arginine infusion, whereas the remaining six patients had virtually zero values throughout the tests. The arginine-induced plasma glucagon rise was similar for the two rates of arginine infusion; the sum of the increments in plasma glucagon averaged 877±120 and 647±92 pg/ml (p>0.1) for the high and low rates of arginine infusion, respectively. The magnitude of the blood glucose rise appeared independent of the amount of arginine infused. Confirming previous reports, we found that the blood glucose rise after arginine was three to four times higher in subjects without C-peptide than in subjects with C-peptide. The mean glucagon response did not differ significantly between subjects with or without C-peptide. Thus, residual B cell function determines the magnitude of the blood glucose rise but not the glucagon response after intravenous arginine.     

Day-to-day variation of continuously monitored glycaemia: A further measure of diabetic instability

Summary Differences between paired blood glucose values during two successive 24-h periods of continuous blood glucose analysis were investigated during 22 studies in seven unstable diabetics, three stable diabetics, and three normal subjects. The absolute means (without regard to sign) of daily differences (MODD) were high in unstable diabetics (36.6 to 158.1 mg/100 ml), intermediate in stable diabetics (10.2 to 35.1 mg/100 ml), and low in normals (6.2 to 8.2 mg/100 ml). MODD was a measure of the blood glucose changes resulting from day-to-day variation in response to therapy that was kept as constant as possible. When therapy was deliberately intensified through the use of four daily injections of short-acting insulin, MODD decreased in five of six such experiments. In two diabetics retested at intervals of 5 to 7 months without change in insulin regimen, MODD values remained similar. MODD quantifies another characteristic of blood glucose behaviour, the between-day variability; this is an important complement of the mean amplitude of glycaemic excursions (MAGE, a measure of within-day variability) and of the mean blood glucose concentration, MBG (the overall level of glycaemia during the variability measurements).This investigation was supported in part by Research Grant AM-10152 from the National Institutes of Health, Public Health Service, and by a grant from the Endicott-Bohn Foundation.     

Metabolic and hormonal investigations in long-term streptozotocin diabetic rats on different dietary regimens

Summary Groups of diabetic rats (65 mg/kg streptozotocin SC) were fed ad lib on three different dietary regimens for 43 weeks: a standard control diet (68% of calories as carbohydrate, 20% as protein, and 12% as fat), a low carbohydrate high protein diet (6% carbohydrate, 63% protein, 31% fat) or a low carbohydrate-high fat diet (5% carbohydrate, 75% fat, 20% protein). The high fat diet resulted in a fall of blood glucose from 700 to 350 mg/100 ml. Rats fed the high protein diet showed a similar initial decrease in blood glucose concentration, and a further improvement was evident from the 28th week on. After 43 weeks blood glucose levels were below 180 mg/100 ml and glycosuria below 100 mg/24 h in all rats fed the high protein diet. When rats exhibiting blood glucose levels below 180 mg/dl were transferred temporarily to standard diet blood glucose levels increased and marked glycosuria was observed. Rats on the standard diet maintained blood glucose concentrations greater than 500 mg/100 ml and glycosuria of about 16 g/24 h throughout the experiment. The pancreatic insulin content at death of rats fed the standard diet or the high fat diet was 1% of normal rats, whereas the values for the rats on the high protein diet were increased to 9%. Animals fed the low carbohydrate diets showed greater weight gain. In the high fat diet group there was a marked rise after 43 weeks in plasma triglycerides, free fatty acids, 3-hydroxybutyrate and acetoacetate in the plasma. Urea excretion was raised in the animals on the high protein diet. Thus, treatment with low carbohydrate diets for 10 months regardless of fat and protein content markedly improved the diabetic state of rats.     

ACTH and cortisol responses to glucagon stimulation.

The effect of the intramuscular injection of various doses of glucagon in 15 healthy subjects was studied. Significant elevations of plasma ACTH, and cortisol were found to occur 3 h after the administration of 4 mg of crystalline glucagon. Mean levels in 7 subjects were for ACTH 44 +/- 30 (SD) pg/ml, and for cortisol 14 +/- 6 (SD) mug/100 ml at the beginning of the test, and rose to 109 +/- 48 (SD) pg/ml and to 23 +/- 5 (SD) mug/100 ml respectively following glucagon. The peak response of ACTH and cortisol was preceded by a significant rise of plasma insulin, by a fall of the blood glucose, which was initially increased by the administration of glucagon, and by the symptoms of nausea and sweating. This study demonstrates that the intramuscluar administration of glucagon (4 mg) provids a potent stimulus to ACTH and cortisol secretion in healthy subjects.     

Lactase deficiency in Jewish communities in Israel

Lactase deficiency and lactose tolerance were studied in several Jewish communities in Israel. Lactase deficiency was found in 60% of biopsied subjects. Forty-one biopsies were peroral and 22, surgical; histologically, the jejunal mucosa of all specimens was normal. Lactose tolerance tests were performed on 217 subjects, 118 patients and 99normals. A low glucose rise was found in 44.4% of Yemenites, 62.5% of North Africans (Sephardi), 72.2% of others (Sephardi), 79.2% of Ashkenazi, 84.2% of Iraqis and 85.0% of others (Oriental); the overall incidence was 71.1%. Statistical analysis confirmed that the population studied was heterogenous. Most subjects with a low glucose rise had symptoms during the test. Milk intake, low in almost all subjects, did not correlate with lactose tolerance. Most lactose intolerant subjects were not aware of milk intolerance; the condition is not usually symptomatic in Israel. Lactase deficiency in various population groups has been reviewed and evidence in favor of a genetic etiology emphasized.The authors wish to thank the staff of the Tel-Aviv Government Municipal Hospitals, in particular, the Department of Pediatrics-B for their help in carrying out this investigation and for permission to study their patients; Dr. A. Adam, Department of Human Genetics, Tel-Aviv University Medical School, for helpful advice and criticism. Blood sugar estimations were performed at the Central Biochemical Laboratory of the Workers Sick Fund, Tel-Aviv.     

Somatostatin infusion in liver cirrhosis: Glucagon control of glucose homeostasis

Summary In order to evaluate the role of glucagon in blood glucose homeostasis in liver cirrhosis, ten normal subjects and ten cirrhotic patients were infused with somatostatin (500 g/h for 5 h) with and without glucagon (3 mg/kg/h) administration. Somatostatin infusion brought about a fall in plasma glucose both in normal (37%) and cirrhotic (41%) subjects in the first 90 minutes. In normal subjects, this was followed by a rise in plasma glucose (147±2 mg/dl at 5 h), while in cirrhotics no rise in plasma glucose was observed (50±1 mg/dl at 5 h). Plasma insulin and glucagon levels were suppressed in both normal and cirrhotic subjects. Addition of glucagon to the somatostatin infusion caused a two fold rise in plasma glucose level to 183±12 mg/dl at 4 h in normal subjects; a much smaller increase was found in the cirrhotic group (105±3 mg/dl at 4 h). When the infusion was stopped, plasma glucose fell both in normal and cirrhotic subjects (102±14 and 87±2 mg/dl at 6 h respectively). Subsequently, hyperglucagonaemia recurred in the cirrhotic patients (319 ±31 pg/ml). A rebound of plasma insulin was observed in normal subjects (47±8 U/ml) which did not occur in the cirrhotics (16±2 U/ml). Thus when both insulin and glucagon were suppressed by somatostatin infusion, euglycaemia occurred in cirrhotic subjects only when glucagon concentration was restored exogenously. We conclude that glucagon is important in glucose homeostasis in patients with liver cirrhosis.     

Carbohydrate Intolerance in Carcinoma of the Lung

Summary: Oral two hour glucose tolerance tests were performed in 53 patients with carcinoma of the lung and in 45 control subjects of comparable age.
In male subjects, mean blood sugars were significantly higher at 90 and 120 minutes after glucose in the patients with cancer, and blood sugar levels greater than 120 mg/100 ml were seen in 69% of men with cancer, as compared with 38% of control subjects. Glucose tolerance improved with the removal of the tumours in a small group of patients.
As a group, men with carcinoma of the lung had higher plasma insulin and plasma growth hormone concentrations than controls, but these changes were not correlated with carbohydrate in-tolerance in individuals. The Impaired tolerance is not due to "starvation diabetes".     

The effects of sucrose meal on insulin requirement in IDDM and its modulation by acarbose

The purpose of the present study was to evaluate the insulin requirement in response to sucrose meal in IDDM and its modulation by a disaccharidase inhibitor, Acarbose. After an overnight fast, the subjects (n = 9) were "hooked" to the artificial pancreas (Biostator) to maintain normoglycemia. Blood glucose and insulin requirement were recorded by the Biostator throughout the experiment. The patients were divided into two groups. In group I, five patients received increasing sucrose load (50, 75 and 100 g) with and without Acarbose 100 mg. After a 50 g sucrose meal with and without Acarbose, the peak postprandial (PP) blood glucose was 118 and 157 mg/dl and the insulin requirement was 3.9 and 7.8 units resulting in free plasma insulin peak of 34 and 59 microU/ml respectively. After a 75 g sucrose meal with and without Acarbose, the peak PC blood glucose was 134 and 166 mg/dl and the insulin requirement was 5.7 and 9.9 units resulting in free plasma insulin peak of 75 and 87 microU/ml. After a 100 g sucrose meal with and without Acarbose the peak PP blood glucose was 131 and 175 mg/dl and the insulin requirement was 6 and 12.8 units resulting in free plasma insulin peak of 50 and 69 microU/ml. In group II, four patients received increasing Acarbose dose with a fixed sucrose load (75 g). The PP blood glucose peaked at 161, 145, 120 and 102 mg/dl after 0, 50, 100, 200 mg of Acarbose respectively. The total insulin requirements were 12.9, 9.6, 4.3 and 3.1 units. The free plasma insulin was decreased by Acarbose treatment while plasma glucagon remained unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)     

Casual blood glucose levels and prevalence of undiscovered diabetes mellitus in Lagos Metropolis Nigerians

A diabetic screening exercise involving 1627 subjects (1050 males and 577 females) was carried out in the Lagos Metropolis of Nigeria. Casual capillary blood glucose and/or urine glucose were tested for by means of dipsticks. The prevalence rates of undetected diabetes in the males and females were respectively 1.5% and 1.9%. Mean (+/- SD) casual blood glucose levels were higher in the females (82.8 (+/- 19.1) mg/100 ml) than in the males (75.9 (+/- 16.2) mg/100 ml). The prevalence of renal glycosuria was 1.3% in the males and 0.2% in the females. The prevalence of diabetes mellitus in the Lagos Metropolis appears high but similar to that in many other countries. The ambient blood glucose in the non-hospitalized subjects also seems to be not significantly different from values reported in other places.     

Manifestation and occurrence of selective adult-type lactose malabsorption in Finnish teenagers

In 1969–1970, a simple random sample of 129 Finnish school-aged children was examined to study selective adult-type lactose malabsorption (SLM) in this age category. SLM was found in 8 children. All subjects were reexamined 5 years later. SLM was reconfirmed in these 8 persons and found in 3 additional subjects who had normal lactose absorption in the first examination. The prevalence of SLM was 9.3%, being 8.5% in the age category 12–15 years and 9.9% in that 16–20 years. Low rise of blood glucose in the lactose tolerance test of the first examination, very low milk consumption, milk intolerance, and history of gastrointestinal symptoms were found to be of low predictive value as indicators of SLM. It was also concluded that information about dietetic sources of lactose is important to persons with SLM, but categorical exclusion of lactose from the diet is not necessary, at least in the Finnish population.The study was supported by the Finnish Cultural Foundation and the Foundation for Pediatric Research in Finland.     

Relationship of glucose intolerance to coronary risk in Afro-Caribbeans compared with Europeans

Summary Afro-Caribbeans have low mortality rates from coronary heart disease, despite a high prevalence of diabetes mellitus. We examined 1166 Afro-Caribbean and European men and women aged 40–64 years in a community survey in London, UK. Prevalence of glucose intolerance (combining impaired glucose tolerance, new and known diabetes) was 31% in Afro-Caribbeans and 14% in Europeans (p<0.001). In men, the prevalence of probable coronary heart disease was 6% in Afro-Caribbeans and 13% in Europeans (p<0.01). Triglyceride was lower in Afro-Caribbeans than Europeans; in men, HDL cholesterol was higher. Afro-Caribbean men were less centrally obese, while Afro-Caribbean women were more centrally obese than their European counterparts. Fasting and 2-h insulin levels were higher in Afro-Caribbeans than Europeans. Glucose intolerance was associated with high triglyceride, low HDL cholesterol and central obesity in European but not in Afro-Caribbean men. In Europeans, fasting triglyceride was 1.49 mmol/l in normoglycaemic and 1.89 mmol/l in glucose intolerant men (p<0.05), in Afro-Caribbean men triglyceride was 1.08 and 1.22 mmol/l, respectively. Waist hip ratio was 0.94 in normoglycaemic, and 0.98 in glucose intolerant European men (p<0.001). In Afro-Caribbean men, waist hip ratio was 0.93 in both groups. At each level of insulin, glucose or central obesity, triglyceride was lower in Afro-Caribbean men and women than in Europeans. We speculate that despite high insulin levels, Afro-Caribbeans have a favourable lipoprotein pattern which persists in the presence of glucose intolerance, and may be related to body fat distribution. This could begin to explain their low rates of coronary heart disease.Abbreviations CHD Coronary heart disease - WHR waist hip ratio - WTR waist thigh ratio - BMI body mass index - NIDDM non-insulin-dependent diabetes mellitus     

Intestinal lactase deficiency in an apparently normal Peruvian population

The prevalence of milk and lactose intolerance and intestinal lactase deficiency was studied in 30 apparently healthy Peruvian individuals. At the same time, 20 milk-intolerant persons were included in the study. According to the results of lactose-tolerance tests and intestinal lactase assays, one-third of the 30 were considered normal and were used as controls. The other two-thirds were found to be abnormal and were referred to asasymptomatics; they tolerated well small amounts of milk consumed daily. Upon lactose load, they developed gastro-intestinal symptoms, and maximal rise of blood glucose was below normal limits. Enzymatic assay indicated that they were deficient in intestinal lactase. The remaining 20 were intolerant to milk and the results of their tests were abnormal. Sucrase activity was similar in the 3 groups. This high incidence of lactase deficiency in apparently normal individuals seems to be acquired.     

Renal function in gout. IV. An analysis of 524 gouty subjects including long-term follow-up studies.

Renal function studies were performed in 524 gouty subjects, including follow-up studies at intervals up to 12 years in 112 of them. In 49 subjects, the glomerular filtration rate was less than 70 ml/min and Curate:glomerular filtration rate ratio tended to rise as the glomerular filtration rate decreased, reflecting a relatively stable urate excretion over varying filtered urate loads. The increment in Tsurate:glomerular filtration rate was small with spontaneous Purate between 7 and 9 mg/100 ml. It was modest with Purate up to 10 mg/100 ml. The increment in Tsurate:glomerular filtration rate became much higher beyond Purate of 10 mg/100 ml. Urinary urate levels above 800 mug/min, designated as excess urate excretion, occurred more commonly in subjects with Purate above 9 mg/100 ml, and with better preserved renal function. Tophi were more frequently observed in subjects with low glomerular filtration rate and proteinuria; but incidence of urolithiasis seemed to be less affected by a decrease in the glomerular filtration rate. Hyperuricemia alone had no deleterious effect on renal function as evidenced by follow-up studies over periods up to 12 years. Deterioration of renal function was largely associated with aging, renal vascular disease, renal calculi with pyelonephritis or independently occurring nephropathy. In only very few instances was diminished renal function ascribable to gout alone.