ABSTRACT
Background: Genetically programmed adult-type hypolactasia affects 56% of Chilean population. Ideally, diagnosis should be confirmed. Aim: To compare diagnostic yield of genetic test, hydrogen (H2) expiratory test and a validated symptomatic structured survey (SS). Material and Methods: Patients submitted to H2 test answered a historic (anamnestic) and current SS (after the ingestion of 25 g of lactose). A blood sample was obtained for determination of genetic polymorphisms C/T_13910, C/G_13907 and G/A_22018 by polymerase chain reaction. The gold standard for diagnosis of lactose intolerance (LI) was the agreement of at least two of three tests. Results: Sixty-one participants aged 39 ± 12 years (21 males), were studied. Anamnestic SS was diagnostic of LI in all cases (score > 7), while current SS detected LI in 27/61 (46%). H2 test (an increase > 15 ppm after ingestion of 25 g of lactose) showed LI in 31/61 (51%). The locus C/G_13907 showed no polymorphism and locus G/A_22018 was in complete linkage disequilibrium with C/T_13910. Genotype C/C_13910, associated to hypolactasia, was present in 30/58 (52%). According to the gold-standard, 32/61 (52.5%) patients were diagnosed as LI. Sensitivity and specificity were, respectively, 79% and 69% for current SS, 93% and 93% for H2 test and 97% and 93% for the genetic test. The last two showed a positive likelihood ratio (LR) > 10 and a negative LR < 0.1, figures within the range considered clinically useful. Conclusions: Genotype C/C_13910 is responsible for hypolactasia in this population. Anamnestic report of symptoms after milk ingestion and symptoms after lactose ingestion, are not accurate enough. H2 and genetic tests are simple and similarly accurate to diagnose lactose intolerance in adults.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Lactose Intolerance/diagnosis , Genotype , Lactase/genetics , Lactose Intolerance/genetics , Lactose Tolerance Test , Polymerase Chain Reaction , Polymorphism, Genetic , Polymorphism, Single Nucleotide , Surveys and Questionnaires , Sensitivity and SpecificityABSTRACT
Se efectuó manometría anorrectal pre y postoperatorio en 15 pacientes portadores de fisura anal, los cuales fueron sometidos a esfinterotomía lateral. Los resultados fueron comparados con un grupo control. La presión de reposo fue significativamente mayor en los pacientes que en el grupo control. (111ñ27 cm H2O vs 70ñ14 cm H2O), luego de la cirugía la presión disminuyó a valores no diferentes de lo normal (80ñ15 cm H2O). El estudio confirma la existencia de una presión de reposo aumentada en portadores de fisura anal, la cual es causada por hiperactividad del esfínter interno anal y la esfinterotomía interna lateral reduce efectivamente la presión anal y permite la cicatrización de la fisura