Increased low back pain prevalence in females than in males after menopause age: evidences based on synthetic literature review

Abstract

Female sex hormones play an important role in the etiology and pathophysiology of a variety of musculoskeletal degenerative diseases. Postmenopausal women show accelerated disc degeneration due to relative estrogen deficiency. This literature review aims to validate or falsify this hypothesis, i.e., while overall females have higher prevalence of low back pain (LBP) across all age groups, this male vs. female difference in LBP prevalence further increases after female menopause age. The literature search was performed on PubMed on January 2, 2016. The search word combination was (low back pain) AND prevalence AND [(males OR men) AND (females OR women)]. The following criteria were taken to include the papers for synthetic analysis: (I) only English primary literatures on nonspecific pain; (II) only prospective studies on general population, but not population with occupational LBP causes, of both males and female subjects studied using the same LBP criterion, ages-specific information available, and males and female subjects were age-matched; (III) studies without major quality flaws. In total 98 studies with 772,927 subjects were analyzed. According to the information in the literature, participant subjects were divided into four age groups: (I) school age children group: 6-19 years; (II) young and middle aged group: 20-50 years; (III) mixed age group: data from studies did not differentiate age groups; (IV) elderly group: ≥50 years old. When individual studies were not weighted by participant number and each individual study is represented as one entry regardless of their sample size, the median LBP prevalence ratio of female vs. males was 1.310, 1.140, 1.220, and 1.270 respectively for the four age groups. When individual studies were weighted by participant number, the LBP prevalence ratio of female vs. males was 1.360, 1.127, 1.185, and 1.280 respectively for the four groups. The higher LBP prevalence in school age girls than in school age boys is likely due to psychological factors, female hormone fluctuation, and menstruation. Compared with young and middle aged subjects, a further increased LBP prevalence in females than in males was noted after menopause age.

Keywords: Physiological gender difference; epidemiology; intervertebral disc degeneration; low back pain (LBP); menopause; menstruation.

Figure 1

Female vs. male low back pain prevalence ratios in four age-specific groups; horizontal bars show the median values. Each individual study is represented as one entry regardless of their sample size.

Figure 2

Female vs. male low back pain prevalence ratio in four age-specific groups. Each individual study is weighted by their sample size, and studies at each age-specific group are summed together.

Figure S1

(A) Prevalence of present back-hip-sciatic pain, by age and sex [modified from Lawrence 1969, UK study (50)]; (B) prevalence of grade 3–4 low back pain according to age and sex [modified from Cho et al. 2012, Korean study (53)]. The data show after menopause women have higher low back pain prevalence than age match men.