Genetic variant of lactase-persistent C/T-13910 is associated with bone fractures in very old age.

OBJECTIVES

To determine the relation between the C/T(-13910) single-nucleotide polymorphism residing 13,910 base pairs from the 5' end of the lactase gene associated with lactase persistence and the occurrence of bone fractures in elderly people.

DESIGN

Population-based study.

SETTING

Vantaa 85+ population-based study, including all 601 subjects born before April 1, 1906, who were living in the city of Vantaa, Finland, on April 1, 1991.

PARTICIPANTS

Four hundred eighty-three people aged 85 and older (106 men and 377 women).

MEASUREMENTS: Genotype determination was made using a polymerase chain reaction minisequencing technique.

RESULTS

The frequency of the genotype C/C(-13910) associated with adult-type hypolactasia (low lactase enzyme activity or primary lactose malabsorption (LM)) was significantly greater in individuals with hip fractures, with an adjusted odds ratio (OR) of 3.7 (95% confidence interval (CI)=1.8-7.8), wrist fractures with an adjusted OR of 2.5 (95% CI=1.2-5.2), and hip and wrist fractures combined with an adjusted OR of 4.1 (95% CI=2.0-8.3).

CONCLUSION

The C/C(-13910) genotype associated with primary LM could represent a genetic risk factor for bone fractures for elderly people.