OBJECTIVES

In Asia, younger individuals (below age 45) are diagnosed to have type 2 diabetes with increased rates of obesity defined by lower BMI yet with greater visceral adiposity (waist circumference and waisthip ratios). The prevalence data on type 1 diabetes is not well established, considered to be low, but is seen to be increasing as well. This changing phenotype therefore, presents a clinical dilemma in terms of correctly classifying diabetes and deciding on the consequent appropriate treatment. Distinguishing type 1 from type 2 diabetes has become more difficult with type 2 diabetes dramatically increasing in young adults and children. This study aims to define the characteristics of diabetes among young adults in the Philippines to provide a basis for appropriate management amidst changes in diabetes phenotypes seen globally.

METHODS

In this cross-sectional analytic study, we characterized the demographic, metabolic, and autoimmune features of diabetes among young adult Filipinos aged 18 to 45 years old consulting at a tertiary referral center in Manila, Philippines. Baseline serum A1c, FBS, 75-g oral glucose tolerance test, insulin, serum C-peptide, insulin autoantibodies, leptin, adiponectin, lipid profile, and thyroid function tests were obtained from the participants and analyzed. The homeostasis model assessment (HOMA) was used to estimate the insulin sensitivity.

RESULTS

A total of 348 patients with diabetes were included, with females comprising two-thirds of the participants. The mean age at diagnosis of diabetes was 35.9±7.22 years. The mean BMI was 28.12 kg/m2, with median waist to hip ratio (WHR) of 0·93. Metabolic syndrome was found in 60% of participants and 67.82% were obese by body mass index. The mean A1c was 9.07±2.52%. Good glucose control (A1c less than 7.0%) was seen in 23% of participants  while nearly half (48%) had HbA1c which was >9.0%. The median levels of fasting insulin and C-peptide were 12.62 (range 1.33–90.42) mIU/L and 0.78 ng/mL (range 0–16.2), respectively. 

Included participants were diagnosed with diabetes within a year and as such, majority did not have any micro- or macrovascular complications. The most common diabetes complication was sensory neuropathy detected by monofilament testing, which was found in 28% of participants, followed by non-proliferative diabetic retinopathy in 13%. A history of previous diabetic ketoacidosis was found in 10 patients (2.87%). Glutamic acid decarboxylase (GAD) and insulin auto-antibodies were found in 3.2% and 19.3% of participants, respectively. Approximately half (51.73%) of the participants were insulin resistant by HOMA-IR.

CONCLUSION

In contrast with Caucasians and other Asians, diabetes among young Filipino adults is associated with lower BMI but with a similarly high visceral adiposity as shown by an elevated WHR. Metabolic syndrome with insulin resistance as defined by a variety of indices is predominant. Type 1 diabetes with autoantibodies occur in only a small fraction of this population. Data derived from this work can provide a framework for cluster analysis towards personalized management specific to this population.

Human ; Acids ; Adiponectin ; Adiposity ; Adult ; Aged ; Antibodies ; Asia ; Asian ; Asian Continental Ancestry Group ; Autoantibodies ; Body Mass Index ; C-peptide ; Carboxy-lyases ; Child ; Cluster Analysis ; Demography ; Diabetes Complications ; Diabetes Mellitus ; Diabetes Mellitus, Type 1 ; Diabetes Mellitus, Type 2 ; Diabetic Ketoacidosis ; Diabetic Retinopathy ; Diagnosis ; Fasting ; Female ; Glucose ; Glucose Tolerance Test ; Glutamate Decarboxylase ; Glutamic Acid ; Insulin ; Insulin Resistance ; Ketosis ; Leptin ; Lipids ; Metabolic Syndrome ; Obesity ; Patients ; Peptides ; Phenotype ; Philippines ; Population ; Prevalence ; Serum ; Therapeutics ; Thyroid Gland ; Thyroid Function Tests ; Young Adult

S-methyl-L-cysteine sulfoxide (SMCO) is a non-protein sulfur-containing amino acid with a variety of functions. There are few reports on the enzymes catalyzing the biosynthesis of SMCO from S-methyl-L-cysteine (SMC). In this study, the flavin-containing monooxygenase gene derived from Schizosaccharomyces pombe (spfmo) was heterologously expressed in Escherichia coli BL21(DE3) and the enzymatic properties of the expressed protein were analyzed. The optimum catalytic conditions of the recombinant SpFMO were 30 ℃ and pH 8.0, under which the enzyme activity reached 72.77 U/g. An appropriate amount of Mg²⁺ improved the enzyme activity. The enzyme kinetic analysis showed that the K_m and k_cat/K_m of SpFMO on the substrate SMC were 23.89 μmol/L and 61.71 L/(min·mmol), respectively. Under the optimal reaction conditions, the yield of SMCO synthesized from SMC catalyzed by SpFMO was 12.31% within 9 h. This study provides reference for the enzymatic synthesis of SMCO.
Schizosaccharomyces/genetics* ; Escherichia coli/metabolism* ; Recombinant Proteins/metabolism* ; Cysteine/biosynthesis* ; Mixed Function Oxygenases/metabolism* ; Schizosaccharomyces pombe Proteins/metabolism* ; Oxygenases/metabolism* ; Kinetics

OBJECTIVE: To investigate the effect of traditional Chinese Five-body balance exercise on patients with preserved ratio impaired spirometry (PRISm). METHODS: Fifteen patients with PRISm and 15 patients diagnosed with chronic obstructive pulmonary disease (COPD) were recruited from the Outpatient Department of Guang'anmen Hospital and Beijing Niujie Health Service Center from April to December, 2023. Participants in both groups attended supervised Five-body balance exercise training twice a week for 12 weeks. Patients with COPD continued their regular medication regimen during the intervention period. The endpoints were mean changes in the 6-min walk test (6MWT), St. George's Respiratory Questionnaire (SGRQ) score, cardiopulmonary exercise testing (CPET), pulmonary function, and scores of COPD assessment test (CAT), modified British Medical Research Council, Self-Rating Anxiety Scale, and Self-Rating Depression Scale from baseline to 12 weeks. Adverse events were monitored throughout the study. RESULTS: The PRISm group showed a significant improvement from baseline to week 12 in 6MWT, SGRQ symptom score, and forced vital capacity (FVC) compared to the COPD group (P<0.05). No significant between-group changes were observed in other outcome measurements (P>0.05). In addition, compared with baseline, both groups exhibited improvements in 6MWT, SGRQ score, and CPET at week 12 (P<0.05). The PRISm group also showed a significant increase in forced expiratory volume in 1 s and FVC, as well as a significant decrease in CAT score at week 12 (P<0.05). No adverse events were reported. CONCLUSION Patients with PRISm may benefit from Five-body balance exercise training, which can improve the exercise capacity, health-related quality of life, and lung function. (Registration No. ChiCTR2200059290).
Humans ; Spirometry ; Male ; Female ; Pulmonary Disease, Chronic Obstructive/therapy* ; Lung/physiopathology* ; Middle Aged ; Exercise Tolerance/physiology* ; Exercise Therapy ; Aged ; Medicine, Chinese Traditional ; Respiratory Function Tests ; East Asian People

OBJECTIVE: To evaluate the effects of Chinese patent medicine Huatuo Zaizao Pill (HTZZ) on neurological function and limb motor in ischemic stroke (IS) patients during convalescence. METHODS: This is a prospective, open-labelled, randomized controlled trial. Patients with IS were recruited from the Neurology Department of Xiyuan Hospital of China Academy of Chinese Medical Sciences from May 2021 to June 2023. Eligible participants were randomly assigned to the HTZZ (40 cases) or control group (40 cases) at a ratio of 1:1. The HTZZ group was treated with oral HTZZ (8 g, thrice daily) combined with conventional treatment, while the control group received only conventional treatment. The treatment duration was 12 weeks. The primary outcome was the change in Modified Ashworth Scale (MAS) score from baseline to week 6 and 12. Secondary outcomes included changes in scores of National Institute of Health Stroke Scale (NIHSS), Fugl-Meyer Assessment (FM), and Barthel Index (BI) from baseline to week 6 and 12, as well as lipid indices after 12 weeks. All adverse events (AEs) were recorded and liver and kidney indices were evaluated. RESULTS: A total of 72 patients completed the study (38 in the HTZZ group and 34 in the control group). Compared with the control group, the HTZZ group demonstrated significant improvements in MAS, NIHSS, FM, and BI scores following 6 and 12 weeks of treatment in both intent-to-treat and per-protocol analyses (all P<0.05). No significant differences were noted between groups in lipid indices, AEs, and liver and kidney dysfunction after 12 weeks (P>0.05). CONCLUSIONS HTZZ alleviated spasticity and enhanced neurological function and prognosis of IS patients during convalescence. However, further evaluation of HTZZ's effect on IS outcomes is warranted in clinical trials with larger sample sizes and extended observation periods. (Trial registration No. NCT04910256).
Humans ; Drugs, Chinese Herbal/pharmacology* ; Male ; Female ; Ischemic Stroke/physiopathology* ; Middle Aged ; Aged ; Recovery of Function/drug effects* ; Convalescence ; Extremities/physiopathology* ; Treatment Outcome ; Prospective Studies

OBJECTIVE: To investigate whether Buyang Huanwu Decoction (BYHWD) had a good curative effect on the neuroprotection of red nucleus neurons after spinal cord injury (SCI) and the possible molecular mechanism. METHODS: Ninety male Sprague-Dawley rats were divided into 5 groups (n=18 per group) according to a random number table, including the control, model, low- (12.78 g/kg, BL group), medium- (25.65 g/kg, BM group), and high-dose BYHWD groups (51.30 g/kg, BH group). A rubrospinal tract transection model in rats was established, and different doses of BYHWD were intragastrically administrated for 4 weeks. The forelimb locomotor function was recorded using the spontaneous vertical exploration test. Cyclic adenosine monophosphate (cAMP) level in red nucleus was detected through an enzyme-linked immunosorbent assay. The morphology and number of red nucleus neurons were observed using Nissl's staining and axonal retrograde tracing by Fluoro-Gold (FG). The expression of cAMP-dependent protein kinase A (PKA), nuclear factor kappa-B (NF-κB) p65, and brain-derived neurotrophic factor (BDNF) in red nucleus were detected using immunohistochemistry and quantitative real-time polymerase chain reaction. RESULTS: Compared with the control group, the utilization rate of bilateral forelimbs, unilateral right forelimbs, proportion of FG-labeled positive neurons, cAMP level, protein expressions of PKA and BDNF, and BDNF mRNA expression were significantly decreased in the model group (P<0.01), while NF-κB p65 was increased in the model group (P<0.01). Compared with the model group, the utilization rate of bilateral forelimbs and unilateral right forelimbs were significantly higher in the BL, BM and BH groups (P<0.01), the proportion of FG-labeled positive neurons, cAMP level, protein expressions of PKA and BDNF and BDNF mRNA expression in all BYHWD groups were increased (P<0.05 or P<0.01), while NF-κB p65 were decreased in all BYHWD groups (P<0.05 or P<0.01). CONCLUSIONS BYHWD possesses a sound neuroprotective effect on red nucleus neurons after SCI, and the efficacy was dose-related. The mechanism may be related to regulating the cAMP/PKA/NF-κ B p65 signaling pathway, finally promoting expression of BDNF.
Animals ; Spinal Cord Injuries/pathology* ; Drugs, Chinese Herbal/therapeutic use* ; Rats, Sprague-Dawley ; Male ; Cyclic AMP/metabolism* ; Transcription Factor RelA/metabolism* ; Cyclic AMP-Dependent Protein Kinases/metabolism* ; Signal Transduction/drug effects* ; Brain-Derived Neurotrophic Factor/genetics* ; Red Nucleus/metabolism* ; Recovery of Function/drug effects* ; Neurons/metabolism* ; Rats

Objective:To retrospectively analyze the results of auditory examination,vestibular function examination and laboratory examination of 63 patients diagnosed as vestibular neuritis.Methods:A total of 63 patients diagnosed with vestibular neuritis hospitalized in the Department of Otolaryngology, Head and Neck Surgery of the Third Affiliated Hospital of Sun Yat-sen University, from October 2012 to December 2022 were recruited. All patients met the diagnostic criteria for the 2022 Bárány association vestibular neuritis. Clinical data and the results of pure tone audiometry, electrocochleogram, video electronystagmogram, caloric test, cervical vestibuloevoked myogenic potential（cVEMP）, ocular vestibuloevoked myogenic potential（oVEMP）, video head impulse test（vHIT） was collected.A total of 63 age-and sex-matched healthy subjects in the physical examination center were randomly selected as the control group. The differences of blood indexs and lipid metabolism indexes between the two groups were compared. Results:In patients with vestibular neuritis, 50 out of 63 patients presented normal threshold in pure tone audiometry, 8 out of 63 patients had bilateral high-frequency sensorineural hearing loss and 5 out of 63 patients had unilateral mild high-frequency sensorineural hearing loss, 56 out of 63 cases completed the electrocochleogram, of which 3 cases had a binaural-SP/AP amplitude ratio≥0.4, 5 cases had monaural amplitude ratio ≥0.4. Fifty-five out of 63 patients completed the caloric test with CP values greater than 30% in all. The ratio of patients completed cVEMP, oVEMP and vHIT were 46 cases, 22 cases and 30 cases, respectively. 17 out of 63 cases completed all the four vestibular function tests. According to these tests, 49 patients could determine the extent of injury，including 27 cases with unilateral superior vestibular nerve injury, 21 cases with unilateral superior and inferior vestibular nerve injury and 1 case with unilateral inferior vestibular nerve injury. There were significant differences in neutrophil value（P<0.001）, lymphocyte value（P<0.005）, neutrophil/lymphocyte ratio（P<0.001） and apolipoprotein A1（P<0.001） between patient group and control group. Inflammatory markers were risk factors for patients with vestibular neuritis. The OR values of neutrophil value and blood neutrophil/lymphocyte ratio were 1.81（1.38-2.37, P<0.001） and 2.11（1.41-3.16, P<0.001）, respectively. Apolipoprotein A1 was a protective factor for patients with vestibular neuritis, and the OR value was 0.004（0.001-0.042, P<0.001）. Conclusion:Electrocochleogram could be used in vestibular neuritis patients with normal pure tone threshold to test whether there is hidden hearing loss in these patients. Neutrophil value, lymphocyte value, neutrophil/lymphocyte ratio and apolipoprotein A1 were correlated with vestibular neuritis. The Neutrophil value and neutrophil/lymphocyte ratio were risk factors for morbidity.
Humans ; Vestibular Neuronitis/physiopathology* ; Retrospective Studies ; Female ; Male ; Audiometry, Pure-Tone ; Hearing Loss, Sensorineural/physiopathology* ; Middle Aged ; Adult ; Vestibular Function Tests ; Vestibular Evoked Myogenic Potentials ; Aged

Objective:This study aimed to compare the effects of cochlear implantation（CI） on vestibular function in patients with large vestibular aqueduct syndrome（LVAS） and in patients with extremely severe deafness with normal inner ear structure. Methods:A total of 28 LVAS patients and 28 patients with normal inner ear structure who suffered from extremely severe deafness were selected. The parameters of caloric tests, bone conduction evoked cervical vestibular-evoked myogenic potentials（cVEMP）, bone conduction evoked ocular vestibular-evoked myogenic potentials（oVEMP） and video head impulse tests（v-HIT） were compared between the two groups before and after CI. The data were analyzed using SPSS 26.0 software. Results:There was no significant difference in the results of the preoperative caloric test, v-HIT, and oVEMP（P1, N1） between the LVAS group and the control group（P>0.05）. Compared to the control group, the LVAS group exhibited a shorter cVEMP P1[（13.41±0.71）ms vs （16.28±0.89）ms, P<0.000 1], shorter N1[（19.83±0.54）ms vs （28.18±1.56）ms, P<0.000 1], higher amplitude[（123.60±83.80）μV vs （73.92±79.85）μV, P=0.049 4] and higher oVEMP amplitude[（16.60±13.87）μV vs （9.96±10.47）μV, P=0.028 5] before CI. The abnormal rate of caloric test increased in both groups after CI（25.00% vs 57.14%, P=0.028 8, 32.14% vs 82.14%, P=0.000 3, respectively）. There was no significant difference in the v-HIT parameters in both groups before and after the operation. As for the LVAS group, there was no statistically significant difference in cVEMP and oVEMP induction rates before and after operation. In the control group, there was a decrease in cVEMP induction rate（96.42% vs 64.28%, P=0.005 2） and oVEMP induction rate（96.42% vs 57.14%, P=0.000 9） after CI. LVAS group showed a shorter cVEMP P1[（13.41±0.71）ms vs （10.30±0.60）ms, P<0.000 1]; shorter cVEMP N1[（19.86±0.53）ms vs （18.97±1.33）ms, P=0.004 7]; decreased amplitude[（124.50±84.86）μV vs （64.35±61.57）μV, P=0.001 0] and shorter oVEMP amplitude[（15.92±13.03）μV vs （9.16±9.20）μV, P=0.009 9] after CI. The oVEMP N1 in the control group was longer than that before operation[（11.73 ± 0.91）ms vs （13.35 ± 2.60）ms, P=0.019 6], whereas there was no significant difference in other VEMP parameters after CI. Conclusion:Before CI, there was no significant difference in the results of the caloric test and v-HIT between the LVAS group and the control group, but the LVAS group exhibited increased sensitivity to acoustic stimulation-induced myogenic potentials. After CI, the function of the semicircular canal was impaired in both groups in the low-frequency area, and remained largely unaffected in the high-frequency area. Additionally, the function of the otolith in the LVAS group was less affected than that in the control group after CI, which may be related to the fact that the enlarged vestibular aqueduct of the LVAS patients acted as the third window of the inner ear.
Humans ; Vestibular Aqueduct/physiopathology* ; Cochlear Implantation ; Male ; Female ; Vestibular Evoked Myogenic Potentials ; Deafness/physiopathology* ; Child ; Adolescent ; Adult ; Young Adult ; Hearing Loss, Sensorineural/physiopathology* ; Vestibular Function Tests

Objective:To evaluate the utility of the Rapid Axial Roll Test （RART）, Supine Roll Test （SRT）, and Lying-Down Test （LDT） in determining the affected semicircular canal in cases of horizontal semicircular canal benign paroxysmal positional vertigo （HSC-BPPV）. Methods:A total of 330 patients diagnosed with HSCBPPV from September 2022 to September 2023 were collected and divided into three groups based on the different positional tests received: ①SRT Group, ②LDT+SRT Group, ③RART+SRT Group. The trial was divided into two stages: LDT/RART for patients in the first stage, and SRT for patients in the second stage. The elicitation rate of nystagmus among the three groups was compared to evaluate the accuracy in determining the affected semicircular canal in HSCBPPV. Results:Nystagmus was elicited in 84.55% （279/330） of the patients by positional tests. The elicitation rate of nystagmus in the RART+SRT/LDT group was 94.55% （104/110）, in the LDT+SRT group it was 84.11% （90/107）, and in the SRT group it was 69.91% （79/113）. The differences among the three groups were statistically significant （χ²= 23.88, P<0.001）. In the ② and ③ groups, there was a statistically significant difference in the elicitation rate of nystagmus between stage Ⅰ （patients with LDT or RART） （χ²=43.842, P<0.001）. SRT was performed in the stage Ⅱ, and there was a statistically significant difference in nystagmus extraction rate between the two groups （χ² =4.690, P=0.030）. The difference in the proportion of agreement between stage Ⅰ（LDT or RART） and stageⅡ （SRT） in determining the affected side of the semicircular canal was also statistically significant （χ² =40.502, P<0.001）. For patients with a consistent diagnosis of the affected semicircular canal, the difference in cure rate was not significant （P=0.149）. The Kappa statistic indicated substantial agreement between RART and SRT in terms of eliciting nystagmus （agreement 96.36%, Kappa = 0.730, P<0.001）. Conclusion:RART and SRT show a high degree of agreement regarding the elicitation rate of nystagmus. RART is simple and safe, and it can effectively induce the characteristic nystagmus of HSC-BPPV, accurately identify the responsible semicircular canal and provide a more optimized examination protocol for clinical practice in HSCBPPV.
Humans ; Semicircular Canals/physiopathology* ; Benign Paroxysmal Positional Vertigo/diagnosis* ; Female ; Male ; Middle Aged ; Nystagmus, Pathologic/diagnosis* ; Vestibular Function Tests/methods* ; Aged ; Vertigo/diagnosis* ; Adult

Objective:To explore of auditory-vestibular function and inner ear imaging features of patients with Meniere's disease（MD） at different clinical stages. Methods:The clinical data of 110 patients with unilateral MD who were admitted from January 2023 to March 2024 were collected, and all patients were staged according to the results of pure tone hearing threshold test, including 13 patients with stage Ⅰ, 18 cases with stage Ⅱ, 65 cases with stage Ⅲ, and 14 cases with stage Ⅳ. All patients were tested for vestibular function, including caloric tests, vestibular evoked myogenic potentials（VEMPs）, vHIT and sensory integration tests（SOT）. The sites of endolymphatic hydrops were evaluated by intravenous endotogidolinium-based MRI, twenty-seven patients completed electrocochleography. Results:①The disease course time of patients with different stages was different, and the disease course time of stage Ⅰ and Ⅱ was shorter than that of stage Ⅲ and Ⅳpatients（P<0.05）. ②No statistical differences were found in clinical data or vestibular function between normal and abnormal ECochG groups（P>0.05）. ③The results of caloric tests showed that the UW% values of stage Ⅲ（45.5±14.79） and stage Ⅳ （51.57±22.44） were higher than those of stageⅠ（31.2±14.9） and stage Ⅱ（33.5±13.31）, there were statistically significant differences between stage Ⅰ and stage Ⅱ with stage Ⅲ and Ⅳ groups（P<0.05）, the total abnormal rate of cVEMP was 62.72%, there was a statistically significant difference between stageⅠand stage Ⅲ with the stage Ⅳ group（P<0.05）, the total abnormal rate of oVEMP was 71.82%, the difference between stage Ⅰ and stage Ⅳ group was statistically significant（P<0.05）. The total score of SOT comprehensive balance gradually decreased with the increase of clinical stage, and there was a significant difference between the stage Ⅰ and Ⅳ groups（H=26.08, P<0.01）, and there was a statistically significant difference in the rate of vestibular dysfunction of SOT between the two groups（χ²=6.7, P<0.05）. ④Patients with vestibular and cochlear endolymphatic hydrops, and patients with simple cochlear or vestibular had significantly differences in disease course time, clinical stages, UW% value of caloric test, abnormal rate of cVEMP and oVEMP, total SOT balance score, the rate of vestibular abnormality（P<0.01）. Among them, when the vestibular and cochlear endolymphatic hydrops are at the same time, the clinical stage of the patient is mainly stage Ⅲand Ⅳ. Conclusion:Auditory-vestibular and inner ear gadolinium-contrasted MRI examinations in clinical practice provide a supplementary reference for judging vestibular function and the type of endolymphatic hydrops.
Humans ; Meniere Disease/diagnostic imaging* ; Ear, Inner/physiopathology* ; Male ; Magnetic Resonance Imaging ; Female ; Middle Aged ; Vestibule, Labyrinth/diagnostic imaging* ; Adult ; Vestibular Evoked Myogenic Potentials ; Aged ; Audiometry, Pure-Tone ; Caloric Tests ; Vestibular Function Tests

Objective:To investigate the potential characteristic manifestations and application value of the Dynamic Visual Acuity Test（DVAT） in vestibular migraine（VM）. Methods:A total of 50 VM patients（case group） and 50 healthy subjects（control group） diagnosed at the Department of Otorhinolaryngology Head and Neck Surgery, First Hospital of Shanxi Medical University between November 1, 2023, and December 31, 2024, were enrolled. The case group underwent DVAT, video head impulse test（vHIT）, caloric test, and Dizziness Handicap Inventory（DHI） assessment, whereas the control group only received DVAT. Group-based analyses were conducted to examine the effect of age on Dynamic Visual Acuity Loss（DVALoss）, as well as the correlations of DVALoss with vestibular function tests and DHI scores. Results:DVALoss in the case group was significantly higher than that in the control group（P<0.001）. In both groups, age was significantly and positively correlated with DVALoss（P<0.001）. Within the case group, DVALoss was strongly and positively correlated with DHI scores（r=0.807, P<0.001）; it was negatively correlated with the vestibulo-ocular reflex（VOR） gain in vHIT, though without clinical significance, and showed no significant association with the caloric test. Age and DVALoss collectively accounted for 71.3% of the variance in DHI scores（R²=0.713）, with age exerting a relatively minor actual impact. Conclusion:DVAT can sensitively identify the core functional impairments of VM. DVALoss, as a direct functional reflection of the pathological mechanism of VM, is strongly correlated with DHI scores. Incorporating DVALoss into standardized assessments may provide an objective basis for the diagnosis and management of VM.
Humans ; Migraine Disorders/diagnosis* ; Visual Acuity ; Case-Control Studies ; Head Impulse Test ; Vestibular Function Tests ; Female ; Male ; Adult ; Vestibular Diseases/physiopathology* ; Middle Aged ; Caloric Tests