title: Lactose absorption in patients with glucose 6-phosphate dehydrogenase deficiency with and without favism.
abstract: BACKGROUND
  It has recently been suggested that primary lactase deficiency might have been selected for by malaria, as has been previously shown to occur for thalasaemia and glucose 6-phosphate dehydrogenase (G6PD) deficiency.
  
  
  OBJECTIVE
  To test this hypothesis, the prevalence of primary lactase deficiency in G6PD deficient subjects and in controls from the area of Sassari (Northern Sardinia) was determined, which in the past was characterised by an intermediate malarial endemicity.
  
  
  METHODS
  70 adult subjects with G6PD deficiency, 34 of whom had a past history of favism, and 50 age matched control subjects.
  
  
  METHODS
  The capacity to absorb lactose was assessed by measuring breath hydrogen production after oral administration of lactose (50 g) by a gas chromatographic method.
  
  
  RESULTS
  Twenty per cent of G6PD deficient subjects with a positive history of favism and 22% of G6PD deficient subjects without a positive history of favism were lactose absorbers compared with 14% lactose absorbers in the control group. The differences were not statistically significant.
  
  
  CONCLUSIONS
  These data show that the prevalence of primary lactase deficiency in the area of Sassari is relatively high, but comparable to that seen in the adult population from another area of southern Italy (Naples) where malaria was less endemic.
authors.affiliation: Department of Paediatrics and Neonatology, University of Sassari, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Meloni
authors.forename: C
authors.initials: C
authors.lastname: Colombo
authors.forename: A
authors.initials: A
authors.lastname: Ogana
authors.forename: M C
authors.initials: MC
authors.lastname: Mannazzu
authors.forename: G F
authors.initials: GF
authors.lastname: Meloni
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005236:Favism / Q000150:complications*; D005260:Female; D006008:Glycogen Storage Disease / Q000150:complications / Q000453:epidemiology / Q000378:metabolism*; D006801:Humans; D006859:Hydrogen / Q000032:analysis; D007558:Italy / Q000453:epidemiology; D007785:Lactose / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D015995:Prevalence
chemical_list: D006859:Hydrogen; D007785:Lactose