UNLABELLED: Adult-type hypolactasia, as mediated by a widespread genetic predisposition, not only reduces calcium intake but also calcium absorption in the presence of high amounts of lactose and may, therefore, promote osteoporosis. A lactose-reduced diet and lactose-free calcium supplements may reverse this imbalance. INTRODUCTION AND HYPOTHESIS: Adult-type hypolactasia (HL) defined by the LCT(-13910) polymorphism may reduce calcium intake by reducing dairy consumption and, therefore, promote osteoporosis. This study aimed to evaluate whether lactose also decreases intestinal calcium absorption in subjects with HL and whether lactose-reduced diet and lactose-free calcium supplementation as recommended could maintain bone mineral density (BMD). METHODS: Based on LCT genotyping, 73 postmenopausal women with and without HL underwent a conventional H(2) breath test with a concomitant oral strontium absorption test lasting 150 minutes, which closely reflects intestinal calcium absorption. In addition, we compared bone-specific laboratory parameters, lumbar and femoral BMD, and spinal radiographs to a similar bone assessment 5 years earlier. RESULTS: LCT genotyping and functional lactose malabsorption tests were highly correlated. Dairy product consumption was reduced by 80% in HL individuals. During concomitant lactose application, mean strontium absorption was blunted by 54% in HL subjects after 150 minutes (1272 +/- 629 microg/L vs. 2020 +/- 1130 microg/L in lactose tolerant subjects, p=0.001). Nevertheless, BMD in HL subjects remained stable with lactose-free calcium supplements during the observation period. CONCLUSION: Both decreased calcium intake as well as lactose-associated impaired calcium absorption may predispose subjects with HL to osteoporosis. Lactose-free calcium supplementation may help to maintain BMD in HL subjects.
UNLABELLED: Adult-type hypolactasia, as mediated by a widespread genetic predisposition, not only reduces calcium intake but also calcium absorption in the presence of high amounts of lactose and may, therefore, promote osteoporosis. A lactose-reduced diet and lactose-free calcium supplements may reverse this imbalance. INTRODUCTION AND HYPOTHESIS: Adult-type hypolactasia (HL) defined by the LCT(-13910) polymorphism may reduce calcium intake by reducing dairy consumption and, therefore, promote osteoporosis. This study aimed to evaluate whether lactose also decreases intestinal calcium absorption in subjects with HL and whether lactose-reduced diet and lactose-free calcium supplementation as recommended could maintain bone mineral density (BMD). METHODS: Based on LCT genotyping, 73 postmenopausal women with and without HL underwent a conventional H(2) breath test with a concomitant oral strontium absorption test lasting 150 minutes, which closely reflects intestinal calcium absorption. In addition, we compared bone-specific laboratory parameters, lumbar and femoral BMD, and spinal radiographs to a similar bone assessment 5 years earlier. RESULTS: LCT genotyping and functional lactose malabsorption tests were highly correlated. Dairy product consumption was reduced by 80% in HL individuals. During concomitant lactose application, mean strontium absorption was blunted by 54% in HL subjects after 150 minutes (1272 +/- 629 microg/L vs. 2020 +/- 1130 microg/L in lactose tolerant subjects, p=0.001). Nevertheless, BMD in HL subjects remained stable with lactose-free calcium supplements during the observation period. CONCLUSION: Both decreased calcium intake as well as lactose-associated impaired calcium absorption may predispose subjects with HL to osteoporosis. Lactose-free calcium supplementation may help to maintain BMD in HL subjects.
Authors: Nicholas J Timpson; Paul Brennan; Valérie Gaborieau; Lee Moore; David Zaridze; Vsevolod Matveev; Neonilia Szeszenia-Dabrowska; Jolanta Lissowska; Dana Mates; Vladimir Bencko; Lenka Foretova; Vladimir Janout; Wong-Ho Chow; Nathaniel Rothman; Paolo Boffetta; Roger M Harbord; George Davey Smith Journal: Cancer Epidemiol Biomarkers Prev Date: 2010-05 Impact factor: 4.254
Authors: K Bácsi; J P Kósa; A Lazáry; B Balla; H Horváth; A Kis; Z Nagy; I Takács; P Lakatos; G Speer Journal: Osteoporos Int Date: 2008-08-13 Impact factor: 4.507
Authors: George Davey Smith; Debbie A Lawlor; Nic J Timpson; Jamil Baban; Matt Kiessling; Ian N M Day; Shah Ebrahim Journal: Eur J Hum Genet Date: 2008-09-17 Impact factor: 4.246
Authors: Johannes Kettunen; Kaisa Silander; Olli Saarela; Najaf Amin; Martina Müller; Nicholas Timpson; Ida Surakka; Samuli Ripatti; Jaana Laitinen; Anna-Liisa Hartikainen; Anneli Pouta; Päivi Lahermo; Verneri Anttila; Satu Männistö; Antti Jula; Jarmo Virtamo; Veikko Salomaa; Terho Lehtimäki; Olli Raitakari; Christian Gieger; Erich H Wichmann; Cornelia M Van Duijn; George Davey Smith; Mark I McCarthy; Marjo-Riitta Järvelin; Markus Perola; Leena Peltonen Journal: Hum Mol Genet Date: 2009-12-16 Impact factor: 6.150