Relationship between fracture risk and second-to-fourth digit ratio (2D:4D) in postmenopausal osteoporosis

Osteoporosis is a metabolic bone disease characterized by decreased bone mass and deterioration of bone microarchitecture, resulting in an increased risk of fractures. This study aims to investigate whether the ratio of the second digit (2D) to the fourth digit (4D) (2D:4D) is a clinically significant biomarker for predicting fracture risk in postmenopausal osteoporosis.

The study included a total of 127 patients, including a postmenopausal patient group aged 50-65 years diagnosed with osteoporosis, and a control group of postmenopausal women without osteoporosis. Participants' age, height, weight, body mass index (BMI), dominant hand, duration of menopause, lumbar spine total L1-L4 T and Z scores and femoral neck T and Z scores measured with dual-energy X-ray absorptiometry (DEXA), Fracture Risk Assessment Tool (FRAX) score, and 2D:4D ratios were recorded. All parameters were compared between the patient and control groups, and correlation analysis was performed between 2D:4D ratios and the total L1-L4 lumbar T score, femoral neck T score, and FRAX scores within the patient group.

Dominant hand, duration of menopause, and BMI were identified as significant parameters affecting the risk of osteoporosis (p < 0.05). Individuals with a dominant left hand had a 3.584-fold higher risk of osteoporosis compared to those with a dominant right hand. A weak, statistically significant negative correlation was found between left hand 2D:4D and major osteoporotic fracture risk (%) and hip fracture risk (%) (p < 0.05).

According to the results of this study, left-hand 2D:4D may have a weak but significant association with the risk of major osteoporotic fractures and hip fractures in the postmenopausal period. Moreover, left-hand dominance is likely to be an independent predictor of osteoporosis risk. These findings support the role of prenatal hormonal influences on bone health in later life.