The function of primary lactase deficiency (PLD) in the development of Postmenopausal osteoporosis is still unclear. This meta-analysis put forward that PLD is a risk factor for osteoporosis in postmenopausal women. Special care is required in these women concerning screening for osteoporosis and its prevention.

Postmenopausal osteoporosis is one of the significant predictors of bone fractures. The analysis involved the execution of a systematic review and meta-analysis of the relationship of bone mineral density (BMD) and primary lactase deficiency (PLD) among postmenopausal women.

Web of Science, PubMed, and Scopus were searched during July 2017 at any publication date and without language limitation. The meta-analyses involved the diagnosis of PLD by genetic testing, or H-2 breath tests and osteoporosis diagnosis by a modern, reliable method for BMD measurement were involved in the evaluation. All the involved papers were reviewed independently and comprehensively by the two investigators. Five of the studies met the inclusion criteria. The data extraction along with data quality and validity assessment was done by using the MOOSE guidelines. The random effects model was used to perform the meta-analysis. 

The inclusion criteria were fulfilled by five case-control studies comprising 2223 participants and 763 lactase-deficient cases. A considerably larger bone density Z-score was found among the absorbers with no notable heterogeneity between the studies. In absorbers, the majority of the measured sites such as Ward's triangle, femoral neck, femoral head, radius, and lumbar spine associated with considerably higher Z-score. No difference was seen in the BMD among absorbers and non-absorbers; however, a substantially greater BMD using g/cm2 was seen among absorbers in the total hip site.

As compared to the healthy controls, postmenopausal women with PLD showed lower Z-scores at most anatomic sites.