Breastfeeding for One Month or Longer is Associated with Higher Risk of Osteoarthritis in Older Adults: NHANES 1999-2012

Female reproductive factors and risk of joint replacement arthroplasty of the knee and hip due to osteoarthritis in postmenopausal women: a nationwide cohort study of 1.13 million women

OBJECTIVES

Previous studies of the relationships between female reproductive factors and osteoarthritis (OA) have shown conflicting results. In this study, we aimed to explore the relationships between reproductive factors and joint replacement arthroplasty of the knee (TKRA) and hip (THRA) in a large nationwide population-based cohort of postmenopausal Korean women.

METHODS

We included 1,134,680 subjects who participated in national health examinations in 2009 in the study. The study outcomes were incident THRA or TKRA due to severe hip or knee OA. The relationships between reproductive factors and THRA or TKRA were evaluated using a multivariable-adjusted proportional hazards model.

RESULTS

During a mean follow-up duration of 8.2 years, 1,610 incident THRA cases and 60,670 incident TKRA cases were observed. Later age at menarche, longer breastfeeding, HRT and OC use were associated with increased risk of TKRA for severe knee OA, while later age at menopause and longer reproductive span were associated with decreased risk. With regard to THRA for severe hip OA, later menarche, longer breastfeeding, HRT more than 5 years, and OC use more than 1 year were associated with higher risk. The associations between reproductive factors and severe OA were more pronounced in underweight and younger subjects.

CONCLUSION

We found that shorter estrogen exposure was associated with higher risk of TKRA due to severe knee OA, and such associations were more pronounced in underweight and younger subjects. The association between shorter estrogen exposure and THRA was not robust.

Relationship of breastfeeding duration with joint pain and knee osteoarthritis in middle-aged Korean women: a cross-sectional study using the Korea National Health and Nutrition Examination Survey

Background

The effect of joint health on the quality of life of middle-aged and older women is becoming more widely recognized with the aging of the world’s population. However, the association of long-term breastfeeding with joint pain and knee osteoarthritis has not been fully examined. The aim of this study was to determine the association of prior breastfeeding duration with current joint pain and knee osteoarthritis in middle-aged Korean women.

Methods

This cross-sectional study was conducted among 3454 women aged ≥50 years who underwent knee radiography and answered a questionnaire on breastfeeding and joint pain for the 5th Korea National Health and Nutrition Examination Survey (2010–2011). After adjusting for confounding sociodemographic, medical history, and obstetric and gynecologic variables, logistic regression analysis was conducted to analyze the prevalence of joint pain and knee osteoarthritis according to breastfeeding and its duration.

Results

Among the 3454 participants, 298 had not breastfed and 1042, 815, and 1299 had breastfed for 1–24, 25–48, and ≥ 49 months, respectively. Of all participants, 1731 had joint pain and 739 were diagnosed with knee osteoarthritis after radiography.

Using the non-breastfeeding group as a reference, the odds ratio (OR) for joint pain among women who breastfed ≥1 month was 1.49 (95% confidence interval [CI] 1.01–2.21). As the breastfeeding duration increased, the OR of joint pain prevalence also increased (p for trend; p = 0.002). For knee osteoarthritis, the OR was 2.30 in the 25–48 months group (95% CI 1.09–4.86). The OR of knee osteoarthritis in the ≥49 months group was 2.17 (95% CI 1.01–4.64). Sensitivity analysis after selecting only participants aged ≥60 years showed that the prevalence of joint pain and knee osteoarthritis was more positively correlated with extended breastfeeding duration (joint pain, p for trend; p = 0.005) (knee osteoarthritis, p for trend; p = 0.012).

Conclusions

Long-term feeding for more than 25 months was associated with an increased prevalence of joint pain and degenerative arthritis in Korean women aged ≥50 years.

Reproductive history and osteoarthritis in the Women's Health Initiative

Objective: To investigate the relationship between self-reported osteoarthritis (OA) and reproductive factors in the Women's Health Initiative (WHI). Method: We used multivariable logistic regression to study the association of self-reported OA and reproductive factors in the WHI Observational Study and Clinical Trial cohorts of 145 965 postmenopausal women, in a retrospective cross-sectional format. Results: In our cohort, we observed no clinically significant associations between reproductive factors and OA given small effect sizes. The following factors were associated with statistically significant increased likelihood of developing OA: younger age at menarche (p < 0.001), history of hysterectomy [adjusted odds ratio (aOR) 1.013, 95% confidence interval (CI) 1.004-1.022, p = 0.04 vs no hysterectomy], history of unilateral oophorectomy (aOR 1.015, 95% CI 1.004-1.026, p < 0.01 vs no oophorectomy), parity (aOR 1.017, 95% CI 1.009-1.026, p < 0.001), ever use of oral contraceptives (aOR 1.008, 95% CI 1.001-1.016, p < 0.01 vs never use), and current use of hormonal therapy (reference current users, aOR 0.951, 95% CI 0.943-0.959 for never users; aOR 0.981, 95% CI 0.972-0.989 for past users; global p < 0.001). Age at menopause, first birth, and pregnancy were not associated with OA. Among parous women, no clear pattern was observed with number of pregnancies, births, or duration of breastfeeding in relation to OA. Conclusion: Our study showed that reproductive factors did not have significant clinical associations with OA after controlling for confounders. This may be due to complex hormonal effects. Additional investigation is warranted in prospective cohort studies. The Women's Health Initiative is registered under ClinicalTrials.gov. Trial registration ID: NCT00000611.