Gender-based comorbidity in benign paroxysmal positional vertigo.

It has been noted that benign paroxysmal positional vertigo (BPPV) may be associated with certain disorders and medical procedures. However, most studies to date were done in Europe, and epidemiological data on the United States (US) population are scarce. Gender-based information is even rarer. Furthermore, it is difficult to assess the relative prevalence of each type of association based solely on literature data, because different comorbidities were reported by various groups from different countries using different patient populations and possibly different inclusion/exclusion criteria. In this study, we surveyed and analyzed a large adult BPPV population (n = 1,360 surveyed, 227 completed, most of which were recurrent BPPV cases) from Omaha, NE, US, and its vicinity, all diagnosed at Boys Town National Research Hospital (BTNRH) over the past decade using established and consistent diagnostic criteria. In addition, we performed a retrospective analysis of patients' diagnostic records (n = 1,377, with 1,360 adults and 17 children). The following comorbidities were found to be significantly more prevalent in the BPPV population when compared to the age- and gender-matched general population: ear/hearing problems, head injury, thyroid problems, allergies, high cholesterol, headaches, and numbness/paralysis. There were gender differences in the comorbidities. In addition, familial predisposition was fairly common among the participants. Thus, the data confirm some previously reported comorbidities, identify new ones (hearing loss, thyroid problems, high cholesterol, and numbness/paralysis), and suggest possible predisposing and triggering factors and events for BPPV

Age and gender distribution of BPPV survey participants (n = 227 total) (A), BPPV cases diagnosed at BTNRH in 2002–2011 (n = 1,377 total) (B), and Nebraska population in year 2010 (n = 1,826,341 total) [73] (C). Recurrent cases are counted only once (the first occurrence).

<p>Age and gender distribution of BPPV survey participants (n = 227 total) (A), BPPV cases diagnosed at BTNRH in 2002–2011 (n = 1,377 total) (B), and Nebraska population in year 2010 (n = 1,826,341 total) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0105546#pone.0105546-USCensus1" target="_blank">[73]</a> (C). Recurrent cases are counted only once (the first occurrence).</p

Incidents and conditions immediately preceding the first BPPV symptoms.

<p>Only those who answered “yes” or “no” were included in the total or subtotal to obtain the percentages. Those who answered “does not apply” or “do not know/remember” were not included in the presented percentages.</p><p>Incidents and conditions immediately preceding the first BPPV symptoms.</p

Demographics of the study population.

<p>Demographics of the study population.</p

Age and gender distribution of non-recurrent (A, n = 1,185 total) and recurrent (B, 192 total) BPPV cases diagnosed at BTNRH from 2002–11.

<p>Age and gender distribution of non-recurrent (A, n = 1,185 total) and recurrent (B, 192 total) BPPV cases diagnosed at BTNRH from 2002–11.</p

Family history of BPPV.

<p>Family history of BPPV.</p

Factors associated with BPPV in females.

<p>The age- and gender-matched control statistics are on the general population in the size of thousands to hundreds of thousands. To simplify the analysis and to provide a conservative estimate of statistical significance, the control population size is set at 1,000 for all diseases for Fisher’s exact test in the table. If no mean prevalence data by meta-analysis are available, the highest prevalence data available for each disease in the control population is used to obtain the two-tailed p values. Significant (or nearly significant) comorbidities are bolded.</p><p>Factors associated with BPPV in females.</p

Effects of comorbid conditions on BPPV recurrence.

<p>The relative risk (RR) and odds ratio (OR) of BPPV recurrence in the presence vs. absence of a comorbid condition were calculated. The actual case numbers (N) are also presented in the order of recurrent/non-recurrent cases with and without the comorbid condition. Fisher’s exact test was used to obtain the two-tailed p values.</p><p>Effects of comorbid conditions on BPPV recurrence.</p