Lactose malabsorption, calcium intake, and bone mass in children and adolescents

Prevalence of lactose intolerance and malabsorption among children of two ethnic groups from the urban areas of Malaysia and its relation to calcium intake and bone health status

Lactase insufficiency could develop into lactose intolerance (LI) and disrupt the intake of calcium, which is a core nutrient for bone development in children. However, data regarding the prevalence of LI and bone health status (BHS) among Malaysian children are scarcely reported.

PURPOSE

This study aimed to determine the prevalence of LI and lactose malabsorption (LM) in Malay and Chinese children and examine its relationship with calcium intake (CI) and BHS.

METHODS

A total of 400 children participated in this study. The prevalence of lactose tolerance (LT) was assessed using hydrogen breath test, LT test, and visual analogue scales. Assessment of CI was performed using a 24-h dietary recall interview (24-h DR) and food frequency questionnaire (FFQ). Calcaneal broadband ultrasound attenuation (BUA) was measured using a quantitative ultrasonometer.

RESULTS

The prevalence of LI among Chinese children (37%) was significantly higher (p = 0.002) than among Malay children (22.5%). However, 61.5% of Malay and 54.5% of Chinese children were found to have LM. CI of the children fulfilled 30.5% and 33.9% of the Malaysian recommended CI (1300 mg/day) for 24-h DR and FFQ, respectively. The BUA score of Malay children was significantly higher (p < 0.001) than that of Chinese children. However, LT and CI were not correlated with BHS (p > 0.05, respectively).

CONCLUSIONS

LI was diagnosed among Malay and Chinese children. However, the higher prevalence of LM is rather worrying as it could develop to LI. The prevalence possibly has been worsened by insufficient CI. Thus, effective approaches to increase CI are highly needed as bone development occurs rapidly at this age and is important for the attainment of the optimum peak bone mass during late adolescence.

Hypocalcemia and Vitamin D Deficiency in Children with Inflammatory Bowel Diseases and Lactose Intolerance

Background: A diet restricted in dairy products can cause calcium and vitamin D deficiency and, secondarily, lead to malnutrition and low bone mass. The aim of the study was to determine the incidence hypocalcemia and vitamin D deficiency in children with inflammatory bowel diseases and lactose intolerance (LI). Material and Methods: A total of 107 patients were enrolled to the study (mean age 14.07 ± 3.58 years; 46.7% boys): 43 with Crohn’s disease (CD), 31 with ulcerative colitis (UC), and 33 with functional abdominal pain (AP-FGID). Hydrogen breath test with lactose and laboratory tests to assess the calcium-phosphate metabolism were performed in all patients. The results of densitometry were interpreted in 37 IBD patients. Results: LI was diagnosed in 23.2% patients with CD, 22.6% with UC, and 21.2% children with AP-FGID, (p = 0.9). Moreover, 9.5% patients with CD, in 21.4% with UC, and in 51.5% with AP-FGID had optimal concentration of 25(OH)D (p = 0.0002). Hypocalcemia was diagnosed in 21% of patients with CD, 16.1% with UC patients, AP-FGID patients had normal calcium levels (p = 0.02). There was no difference in concentrations of total calcium, phosphorus, and 25(OH)D between patients on low-lactose diet and normal diet (p > 0.05). BMD Z-score ≤ −1 SD was obtained by 12 CD patients (48%), and 6 with UC (50%). Conclusion: The use of a low-lactose diet in the course of lactose intolerance in children with inflammatory bowel diseases has no effect on the incidence of calcium-phosphate disorders and reduced bone mineral density.

Lactose intolerance in children and adults

Lactose is a disaccharide found in milk and dairy products. Children and adults with lactose intolerance are unable to tolerate significant amounts of lactose because of an inadequate amount of the enzyme lactase. The condition occurs in three main types: primary, secondary, and primary adult-type hypolactasia. The use of milk in the diet of these individuals may lead to appearance of the irritable bowel syndrome. In persons with lactose intolerance symptoms include diarrhoea, dominated by abdominal colic, loud peristaltic sounds, increased flatulence and meteorism. A diagnosis of lactose intolerance can usually be made with a careful history, elimination of lactose from the diet, lactose tolerance test, hydrogen breath test and genetic testing. In the absence of appropriate tests in patients with suspected primary adult-type hypolactasia, diagnosis can be made as in patients with food allergy. Treatment is based on the restriction of lactose intake with the use of fermented milk products. However, especially for children, if milk and dairy products are eliminated from the diet, it is important to ensure D vitamin and calcium supplementation.

ANALYSIS OF LACTOSE INTOLERANCE IN STUDENTS WITH SUGGESTIVE SYMPTOMS OF IRRITABLE BOWEL SYNDROME

BACKGROUND

Irritable bowel syndrome is a clinical condition presenting pain, distension and abdominal fullness, diarrhea, constipation, and other symptoms. It generates significant impacts on the quality of life of those affected. The pathophysiology is uncertain, but the role of various food types has been established in bowel sensitivity and its clinical manifestations. Carbohydrate intolerance, particularly to lactose, generates similar and sometimes indistinguishable symptoms from irritable bowel syndrome, and in clinical practice is both a frequent and underdiagnosed condition. Carbohydrate intolerance is related to enzymatic deficiencies, alterations of intestinal microbiota and even genetic change. The principal test for a diagnosis of lactose intolerance is the breath test, which measures hydrogen emission (produced only by bacteria), after ingestion of the corresponding substrate.

OBJECTIVE

The present work aims to verify the prevalence of lactose intolerance in university students, presenting gastrointestinal symptoms suggestive of irritable bowel syndrome.

METHODS

In a transversal study, to screen for those with suggestive symptoms, 124 medicine students participated by responding to a form. Those with abdominal pain were referred for anti-parasite treatment in order to exclude intestinal parasites as a secondary cause. Subsequently, using the hydrogen breath test, bacterial overgrowth was investigated, and if negative, lactose intolerance testing would be performed. Patients presenting high hydrogen concentrations of ≥20 ppm above the basal level were considered lactose intolerant.

RESULTS

Of the total of students researched (n=124), 7 were excluded because they did not completing all study phases. From those 117 individuals effectively included in the survey; 8 (6.8%) were diagnosed with lactose intolerance and 2 (1.7%) with bacterial overgrowth. Intolerance was more frequent in; female individuals (75%), age range 18 to 25 years (62.5%), being colored (50%), and in their 5th semester of studies (37.5%). The presence of at least one gastrointestinal symptom among those presenting intolerance (100%), and those not presenting intolerance (42.2%) was found (P=0.002). In addition to abdominal pain (100%) (P<0.001), the most recurrent gastrointestinal symptom in the lactose intolerant students was the distension/flatulence (62.5%) (P=0.026). In relation to life habits and food patterns, there was no statistical difference between lactose tolerant and intolerant individuals, or for symptom frequencies. The more advanced students, completing more periods towards graduation, demonstrated more occurrences of gastrointestinal symptoms, yet without presenting significant statistical discrepancies.

CONCLUSION

In view of the test sample quantity (n=21), a high prevalence of lactose intolerance (6.8%) in the academic environment, with epidemiological characteristics compatible to those found the literature is demonstrated, generating knowledge with understanding to prevent, diagnose, alleviate and treat lactose intolerant university students, and generate positive impacts towards well-being, improving the quality of life of these individuals.

Cow milk protein allergy and other common food allergies and intolerances

The prevalence of food allergy and food intolerance is increasing and it is an important public health problem affecting children. Food allergy results from an immunological reaction to certain food(s) and affects numerous organs in the body. Food intolerances are non-immunological reactions including metabolic, toxic, pharmacological and undefined mechanisms. Cow milk is the most common cause of food allergy and food intolerance, especially in young children. Food intolerance can present with similar symptoms to those of food allergy. Health-care personnel, patients and their caregivers often confuse food intolerance with food allergy. This review focuses on the clinical manifestations, diagnostic evaluation, treatment and prevention of food allergy and food intolerance.

Intestinal fructose malabsorption is associated with increased lactulose fermentation in the intestinal lumen

OBJECTIVE

To study fructose malabsorption in children and adolescents with abdominal pain associated with functional gastrointestinal disorders. As an additional objective, the association between intestinal fructose malabsorption and food intake, including the estimated fructose consumption, weight, height, and lactulose fermentability were also studied.

METHODS

The study included 31 patients with abdominal pain (11 with functional dyspepsia, 10 with irritable bowel syndrome, and 10 with functional abdominal pain). The hydrogen breath test was used to investigate fructose malabsorption and lactulose fermentation in the intestinal lumen. Food consumption was assessed by food registry. Weight and height were measured.

RESULTS

Fructose malabsorption was characterized in 21 (67.7%) patients (nine with irritable bowel syndrome, seven with functional abdominal pain, and five with functional dyspepsia). Intolerance after fructose administration was observed in six (28.6%) of the 21 patients with fructose malabsorption. Fructose malabsorption was associated with higher (p<0.05) hydrogen production after lactulose ingestion, higher (p<0.05) energy and carbohydrate consumption, and higher (p<0.05) body mass index z-score value for age. Median estimates of daily fructose intake by patients with and without fructose malabsorption were, respectively, 16.1 and 10.5g/day (p=0.087).

CONCLUSION

Fructose malabsorption is associated with increased lactulose fermentability in the intestinal lumen. Body mass index was higher in patients with fructose malabsorption.

Assessment of Lactose-Free Diet on the Phalangeal Bone Mineral Status in Italian Adolescents Affected by Adult-Type Hypolactasia

Adult-type hypolactasia (ATH) is a clinical syndrome of primary lactase deficiency. A lactose-free diet is advisable to avoid the symptoms linked to the condition, but this potentially creates problems for optimal bone mineralization due to reduced calcium intake. To evaluate the effect of the lactose-free diet on the bone mineral status (BMS), we compared the phalangeal BMS of adolescents with ATH to that of peers on a normal diet. Also, we analyzed the correlations between BMS and dietary behavior, physical exercise, and calcium and vitamin D intake. A total of 102 cases and 102 healthy controls filled out a diet record and underwent phalangeal Quantitative Ultrasound (QUS). No difference in BMS was observed. The time spent on lactose-free diet (4.8 ± 3.1 years) was inversely correlated to the BMS. More than 98% of cases consumed lactose-free milk, but calcium and vitamin D intake were significantly lower. Calcium intake was correlated to physical exercise but not to BMS. Our results suggest that a lactose-free diet does not affect the phalangeal BMS of adolescents with primary lactase deficiency when their diet includes lactose-free cow’s milk. However, there is still a significantly lower calcium intake than in the population reference. The inverse correlation observed between the BMS and the time spent on a lactose-free diet suggests that a long-term follow-up is advisable.

Lactose intolerance: lack of evidence for short stature or vitamin D deficiency in prepubertal children

BACKGROUND

The health consequences of lactose intolerance (LI) are unclear.

AIMS

To investigate the effects of LI on stature and vitamin D status.

HYPOTHESES

LI subjects will have similar heights and vitamin D status as controls.

SUBJECTS AND METHODS

Prepubertal children of ages 3-12 years with LI (n=38, age 8.61 ± 3.08y, male/female 19/19) were compared to healthy, age- and gender-matched controls (n=49, age 7.95±2.64, male/female 28/21).

INCLUSION CRITERIA

prepubertal status (boys: testicular volume <3cc; girls: Tanner 1 breasts), diagnosis of LI by hydrogen breath test, and no history of calcium or vitamin D supplementation. Vitamin D deficiency was defined as 25-hydroxyvitamin D [25(OH)D] <50 nmol/L. Gender-adjusted midparental target height (MPTH) z-score was calculated using NCHS data for 18 year-old adults. Data were expressed as mean ± SD.

RESULTS

There was no significant difference in 25(OH)D between the LI and non-LI subjects (60.1±21.1, vs. 65.4 ± 26.1 nmol/L, p = 0.29). Upon stratification into normal weight (BMI <85(th) percentile) vs. overweight/obese (BMI ≥85(th) percentile), the normal weight controls had significantly higher 25(OH)D level than both the normal weight LI children (78.3 ± 32.6 vs. 62.9 ± 23.2, p = 0.025), and the overweight/obese LI children (78.3±32.6 vs. 55.3±16.5, p = 0.004). Secondly, there was no overall difference in height z-score between the LI children and controls. The normal weight LI patients had similar height as normal controls (-0.46 ± 0.89 vs. -0.71 ± 1.67, p = 0.53), while the overweight/obese LI group was taller than the normal weight controls (0.36 ± 1.41 vs. -0.71 ± 1.67, p = 0.049), and of similar height as the overweight/obese controls (0.36 ± 1.41 vs. 0.87 ± 1.45, p = 0.28). MPTH z-score was similar between the groups.

CONCLUSION

Short stature and vitamin D deficiency are not features of LI in prepubertal children.