Lactose Intolerance among Malay and Orang Asli Female Children in Selected Rural Selangor and Its Effect on Bone Mineral Density

Sufficient intake of calcium during childhood is very important to ensure an optimal growth and strong bones development. However, lactose intolerance (LI) may limit the intake of milk and dairy products due to the inability of the body to digest lactose to its constituents, glucose and galactose. Children in rural area were a major concern as they are commonly associated with an inadequate intake of nutrients. Hence, the objectives of this study are to determine the prevalence of LI among Malay and Orang Asli female children in rural Selangor and its association with bone mineral density (BMD). A total of 65 (39 Malay, 26 Orang Asli) female primary school students with a mean age of 10.4 +/- 0.6 years old underwent hydrogen breath test and lactose tolerance test (LTT) during fasting and after ingestion of 25g lactose solution. A Wong Baker Face Pain Rating Scale (WBFPRS) was used to assess the presence of gastrointestinal (GI) symptoms during the study. LI symptoms are defined when breath H-2 levels exceed 20 ppm above baseline values, an increase of postprandial blood glucose (PBG) levels of less than 1.1 mmol/L and GI symptom score is more or equal than score 2. BMD was measured in the calcaneus using QUS-2 Ultrasonometer. The result showed that 35 subjects (15 Malay, 20 Orang Asli) had a positive breath test (>20ppm). A total of 74.4% Malay and 88.5% Orang Asli children had an increase of PBG of less than 1.1 mmol/L. Both groups have low percentage (35.9 % Malay, 34.6 % Orang Asli) of GI symptoms. A total of 20.0% children (n=13, Malay=4, Orang Asli=9) was found to experience LI. Orang Asli children showed a significantly higher (p<0.001) BMD (95.7 +/- 11.0 dB/MHz) compared to Malay children (71.7 +/- 8.6 dB/MHz). The result shown there is an association between LI with BMD (p=0.031). Hence, LI does affect in decreasing an individual BMD. In conclusion, the prevalence of LI among female children in rural Selangor is low. However, the relationship between LI and BMD shown in this study need to be addressed carefully starting from an early age as insufficient intake of calcium can affect bone health development needed throughout their entire life.