Why is osteoarthritis more common in women?

Why Osteoarthritis is More Common in Women

Osteoarthritis is more common in women due to a combination of hormonal factors, particularly estrogen decline after menopause, anatomical differences, and sex-specific risk factors. 1

Key Epidemiological Evidence

• Women have a slightly greater prevalent risk of hand osteoarthritis than men, with relative risks of 1.23 (95% CI 1.11 to 1.34) for prevalence 1
• The gender difference in osteoarthritis is age-dependent - women have lower incidence before age 40 but significantly higher incidence after this age 1
• Globally, women account for approximately 60% of people with osteoarthritis, with the disparity becoming more pronounced after age 40 2

Hormonal Factors

• Sex hormones, particularly estrogen, play a significant role in the development of osteoarthritis in women 1
• The dramatic increase in osteoarthritis incidence after menopause suggests that estrogen reduction is a key factor 1, 2
• Estrogen deficiency may unmask symptoms of osteoarthritis by enhancing pain sensitivity 1
• Menopausal status is recognized as an independent risk factor for hand osteoarthritis 1
• Estrogen deficiency can induce loss of intestinal barrier function, leading to endotoxemia and increased inflammatory markers that may contribute to joint degradation 1

Reproductive Factors

• Higher parity (number of children) is associated with increased risk of severe knee osteoarthritis requiring total knee replacement, with women having ≥5 children showing the highest risk (HR 2.01,95% CI 1.50-2.70) compared to nulliparous women 3
• Earlier age at menarche and use of oral contraceptives have been significantly associated with increased risk of total knee replacement in a stepwise manner 3

Anatomical and Biomechanical Factors

• Women have differences in joint anatomy, alignment, and muscle strength that may contribute to their higher osteoarthritis risk 2
• Greater forearm muscle strength and joint laxity are recognized risk factors for hand osteoarthritis that may affect women differently 1
• Women experience greater limitations in physical function and performance than men, independent of BMI, osteoarthritis severity, injury history, and amount of weekly exercise 2

Pain Perception and Clinical Course

• At the same radiographic severity, women report greater pain severity than men 2
• This may be explained by biologically distinct pain pathways, differential activation of central pain pathways, and differences in pain sensitivity and perception 2
• Women have greater use of analgesic medications but less use of arthroplasty and poorer prognosis after surgical interventions 2

Obesity as a Sex-Specific Risk Factor

• Obesity is a significant risk factor for osteoarthritis in both weight-bearing and non-weight-bearing joints 1
• The effect of parity on osteoarthritis risk is significantly stronger among lean women compared to heavier women 3
• Obesity may contribute to hormonal perturbations that persist into menopause 4

Clinical Implications

• Recognizing the higher prevalence of osteoarthritis in women after age 40 should prompt earlier screening and intervention 1
• Muscle strengthening, particularly of the quadriceps, is essential as muscle weakness is both a risk factor and consequence of osteoarthritis 5, 6
• Weight management is crucial for women at risk of osteoarthritis 5, 6

Common Pitfalls in Management

• Failing to consider hormonal factors when evaluating osteoarthritis risk in women 1
• Not addressing modifiable risk factors such as obesity, muscle weakness, and biomechanical issues 5
• Overlooking the need for sex-specific treatment approaches given the differences in disease manifestation and progression 2