Dizziness in peri- and postmenopausal women is associated with anxiety: a cross-sectional study

Women who are in the menopausal transition and postmenopausal periods are affected by a variety of symptoms, such as hot flashes, night sweats, vaginal dryness, depression, anxiety, and insomnia. Non-specific somatic symptoms are also common, including muscle and joint pain, tiredness, and dizziness. Dizziness, which is “an imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness,” according to the Medical Subject Headings of the United States National Library of Medicine [1], is often used interchangeably for vertigo, presyncope, disequilibrium, or lightheadedness. The symptom is itemized in most menopausal symptom inventories, such as “feeling dizzy or faint” in the Greene Climacteric Scale [2], or “dizzy spells” in the Women’s Health Questionnaire [3]. There may be some ethnic differences in the prevalence of the symptom in middle-aged women, as shown in a study by Anderson et al., in which 25.1% of Australian local residents aged 45–60 years reported “feeling dizzy or faint” at least a little, while 41.8% of their Japanese counterparts suffered from the symptom (p < 0.001, chi-squared test) [4].

However, despite its prevalence, the precise mechanisms underlying dizziness in middle-aged women have yet to be elucidated, though some hypotheses have been proposed. For example, Yang et al. recently reported that ovariectomized mice have significant balance behavioral deficits probably because the estrogen deficiency compromises otoconia maintenance and anchoring by reducing the expression of the otoconial component and anchoring proteins [5]. Therefore, in the present study, we sought to determine the prevalence of dizziness in Japanese middle-aged women who were attending a menopause clinic and to investigate the factors associated with the symptom in this population.

The average age of the participants was 51.2 ± 5.0 years (mean ± standard deviation). The rates (0–1 times per month, 1–2 times per week, 3–4 times per week, and almost every day) of dizziness among the 471 women screened are shown in Table 1. The percentage of women who complained of dizziness once a week or more frequently was 35.7%.

The variables that significantly differed (p < 0.20) at the univariate level between the women with (n = 168) and without (n = 303) dizziness were as follows: age (y); body weight (kg); BMI (kg/cm²); body fat (%); muscle mass (kg); waist-to-hip ratio (%); systolic pressure (mmHg); reaction time (cm); the vasomotor, insomnia, depression, and anxiety symptom scores; the habit of regular exercise; and alcohol consumption. Compared to the women without dizziness, those with the symptom were younger; had a higher body weight, BMI, body fat percentage, muscle mass, and waist-to-hip ratio; had higher systolic pressure; were slower in reaction time; had higher physical and psychological symptom scores of menopause; exercised less regularly; and consumed less alcohol (Table 2).

Of these variables, body weight and body fat had significant multicollinearity with the BMI (Pearson’s r/p: 0.906/< 0.05 and 0.917/< 0.05, respectively), and they were excluded from the following multivariate logistic regression analysis. Of the remaining factors, the HADS’ anxiety score was revealed to be the sole factor that was independently associated with dizziness (adjusted odds ratio 1.14; 95% confidence interval 1.08–1.20) (Table 3).

A multivariate logistic regression analysis using a stepwise variable selection procedure was performed to identify the independent risk factors.

In our analysis of 471 middle-aged women, more than one third suffered from dizziness once a week or more frequently, and the sole factor that was independently associated with the symptom was revealed to be anxiety. The percentage of women who experienced dizziness in our study participants, who were aged 40–65 years and recruited in a clinical setting (35.7%), is close to that observed in the Japanese local residents aged 45–60 years in Anderson’s study (41.8%), which was significantly higher than that in Australian local residents in the same study (25.1%) [4]. This gap in the prevalence of dizziness in middle-aged women could be attributable to ethnic differences in the biological mechanisms underlying the symptoms, or to ethnic differences in the somatization of anxiety, considering that the association between dizziness and anxiety was confirmed in the current study. Interestingly, when Hoge et al. compared the somatic and psychological symptoms of Nepali and American patients diagnosed with generalized anxiety disorder, they found that the somatic symptom scores, including that of dizziness, were significantly higher in the former, while the psychological symptom scores were higher in the latter, possibly due to the differences in the cultural traditions of describing emotional distress [22].

Dizziness and anxiety have long been known to coexist, and a bidirectional relationship has been presumed in terms of dizziness-evoked anxiety (a somatopsychic model) and anxiety-evoked dizziness (a psychosomatic model) [23]. A number of hypotheses have been proposed to explain the mechanisms underlying this interplay based on the findings obtained from animal studies. For example, in rats subjected to hypergravity generated by centrifugation, the vestibular stimuli activated the central nucleus of the amygdala, which is a crucial locus for retaining the memory of stimuli for conditioned fear and taste-aversion learning, as determined by the induction of the Fos expression [24]. On the other hand, guinea pigs chronically administered with vasopressin, which is a small neuropeptide produced by the hypothalamic neurons that respond to stressful environmental challenges, developed endolymphatic hydrops (as defined by the increase in the scala media area in the mid-modiolar sections of the cochlea), which mimics the pathology of Meniere’s disease [25].

Furthermore, the concept of “psychiatric dizziness” is supported by the clinical observations that some dizziness occurs exclusively in combination with other symptoms as part of a recognized psychiatric symptom cluster and that this symptom cluster is not itself related to vestibular dysfunction [26]. It is also supported by the finding that psychotherapy, such as cognitive behavioral therapy combined with relaxation techniques with or without vestibular rehabilitation, is effective for improving dizziness to some extent [27]. The finding of the current study that the anxiety symptom score was the sole factor that was independently associated with dizziness in peri- and postmenopausal women highlights that the association between these two symptoms also occurs in this specific population.

Although the multiple logistic regression analysis eliminated psychological symptoms of menopause other than anxiety as factors independently associated with dizziness, depression is also an established contributor to the symptom. Horii et al. revealed that a selective serotonin reuptake inhibitor fluvoxamine improved dizziness in male and female patients whose HADS score decreased with the treatment, suggesting that some of the symptoms were induced by depression [28]. In the same study, HADS-anxiety subscale and depression subscale showed a high correlation both in pre- and post-treatment periods, suggesting that anxiety and depression symptoms were closely related with each other in the patients suffering from dizziness. Our finding that anxiety is the only factor independently associated with dizziness implies that the anxiety was slightly more interconnected with dizziness than depression in the group of women with the symptom in our current study population.

The fact that dizziness is one of the symptoms that middle-aged women most frequently complain about, combined with the report from a hospital survey in Omaha, Nebraska that found that the estimated prevalence (per 100,000 local residents) of benign paroxysmal positional vertigo (BPPV) in women sharply rose from 77.2 in their thirties to 149.7 in their forties and kept increasing to the level of 263.5 in their seventies (compared to that in men, which was 38.2 in their thirties, 47.5 in their forties, and 181.0 (11.4%) [29]), implies that estrogen fluctuation and deficiency in peri- and postmenopausal women might play a role in the pathogenesis of BPPV, as well as a wider spectrum of dizziness. A recent animal study supports this hypothesis as it revealed that ovariectomized mice have significant balance behavioral deficits and that estrogen deficiency compromises otoconia maintenance and anchoring by reducing the expression of otoconial component and anchoring proteins, in addition to causing ectopic debris formation in the ampulla due to aberrant matrix protein expression [5]. More clinically, a placebo-controlled randomized controlled trial in Sweden demonstrated that hormone therapy significantly decreased sway velocity in elderly women who had low levels of baseline serum estradiol [30], which is in line with a cross-sectional analysis in Brazil that showed that hormone therapy users had significantly smaller oscillation than non-users, independent of the muscle strength in their lower limbs [31].

However, the ratio of women with the status of premenopausal/perimenopausal/postmenopausal/surgical menopause was not significantly different in the groups with and without dizziness in our current analysis (Table 2), which suggests that the subjective complaint of dizziness in this population was not affected by the sufficiency, deficiency, or fluctuation of estradiol. The discrepancy could be explained by a difference between the mechanisms underlying BPPV or impaired postural balance and the general dizziness experienced by peri- and postmenopausal women.

The present study was limited by the relatively narrow study population, which included only middle-aged women attending our menopause clinic. It is therefore difficult to extrapolate our results to a wider population. The history of the dizziness was not taken in detail, and the vestibular function of the participants was not evaluated. Furthermore, the cross-sectional design of this study prevented the determination of a causal relationship between the dizziness and anxiety.

Dizziness is highly prevalent in Japanese peri- and postmenopausal women and it is associated with anxiety. The treatment of anxiety in this population might improve the symptom.