Search PubMed⌕ Search

Biomedical subjects

H Pols

Publications and source records attributed to H Pols.

At least 19 recordsLinked to original sources
PubMed1998

Reliability of the 35% carbon dioxide panic provocation challenge.

The objective of this study was to determine the test-retest reliability of the 35% carbon dioxide (CO2) panic provocation challenge. Thirty patients with panic disorder were included in this study. Twenty-four patients were challenged twice, with 1 week between the two challenges. Six patients dropped out after the first test. The 35% CO2 challenge appeared to have a good test-retest reliability; both on induced subjective anxiety, measured on a Visual Analogue Scale for Anxiety (VAS-A), and induced panic symptoms, measured with a Panic Symptom List. Assessing the state of anxiety immediately after the challenge gave the most reliable results. Calculating increase in anxiety from the pre- and post-scores on the VAS-A rendered less reliable scores. This study completes a series of studies in which the criteria for an ideal model of panic are tested for the 35% CO2 challenge. Apart from an absolute specificity for panic disorder, the challenge meets these criteria.

Adult↗
PubMed1998

Comorbid depressive disorder increases vulnerability to the 35% carbon dioxide (CO2) challenge in panic disorder patients.

BACKGROUND: The hypothesis of this study was that panic disorder patients with a comorbid depressive disorder would be less vulnerable to the 35% CO2 panic provocation challenge than panic disorder patients without a comorbid depressive disorder. This hypothesis was based on findings from ventilatory response studies in depressive patients. METHODS: Twelve panic disorder patients with and 23 panic disorder patients without a comorbid depressive disorder were challenged. RESULTS: Panic disorder patients with a comorbid depressive disorder scored significantly higher on ratings of subjective anxiety and panic symptoms induced by the challenge. CONCLUSIONS: A comorbid depressive disorder appeared to increase the vulnerability of panic disorder patients to this panic provocation. LIMITATION: We did find significant differences, but these differences did not confirm the original hypothesis. CLINICAL RELEVANCE: Our results support clinical data that show that a comorbid depressive disorder correlates with an increased severity of panic disorder.

Adult↗
PubMed1997

Population-based geographic variations in DXA bone density in Europe: the EVOS Study. European Vertebral Osteoporosis.

The purpose of this study was to investigate variations in bone density between 16 European populations, 13 of which were participants in the European Vertebral Osteoporosis Study (EVOS). Men and women aged 50-80 years were recruited randomly from local population registers, stratified in 5-year age bands. The other three centres recruited similarly. Random samples of 20-100% of EVOS subjects were invited for dual-energy X-ray absorptiometry (DXA) densitometry of the lumbar spine and/or proximal femur using Hologic, Lunar or Norland pencil beam machines or, in one centre, a Sopha fan-beam machine. Cross-calibration of the different machines was undertaken using the European Spine Phantom prototype (ESPp). Highly significant differences in mean bone density were demonstrated between centres, giving rise to between centre SDs in bone density that were about a quarter of a population SD. These differences persisted when centres using Hologic machines and centres using Lunar machines were considered separately. The centres were ranked differently according to whether male or female subjects were being considered and according to site of measurement (L2-4, femoral neck or femoral trochanter). As expected, bone mineral density (BMD) had a curvilinear relationship with age, and apparent rates of decrease slowed as age advanced past 50 years in both sexes. In the spine, not only did male BMD usually appear to increase with age, but there was a highly significant difference between centres in the age effect in both sexes, suggesting a variability in the impact of osteoarthritis between centres. Weight was consistently positively associated with BMD, but the effects of height and armspan were less consistent. Logarithmic transformation was needed to normalize the regressions of BMD on the independent variates, and after transformation, all sites except the femoral neck in females showed significant increases in SD with age. Interestingly, the effect of increasing weight was to decrease dispersion in proximal femur measurements in both sexes, further accentuating the tendency in women for low body mass index to be associated with osteoporosis as defined by densitometry. It is concluded that there are major differences between BMD values in European population samples which, with variations in anthropometric variables, have the potential to contribute substantially to variations in rates of osteoporotic fracture risk in Europe.

Absorptiometry, Photon↗
PubMed1996

Alprazolam premedication and 35% carbon dioxide vulnerability in panic patients.

A group of 20 patients who met the DSM-III-R criteria for panic disorder with or without agoraphobia underwent a 35% carbon dioxide (CO2) challenge after either 1 mg alprazolam or placebo in a double-blind, randomized, cross-over design. Despite the anxiolytic potential of alprazolam, it produced no significant effects on CO2-induced anxiety and panic symptomatology when compared to placebo.

Adult↗
PubMed1995

Respiratory disorders as a possible predisposing factor for panic disorder.

150 consecutive anxiety patients completed a specially designed questionnaire which asked for the occurrence of respiratory and other somatic disorders before the onset of their anxiety disorder. The sample was divided into 82 panic disorder patients and 68 other anxiety patients serving as controls. Panic disorder patients had a significantly higher prevalence of respiratory diseases before the onset of their anxiety disorder than controls (42.7 vs. 16.2%). This higher prevalence was mainly due to a higher prevalence of bronchitis (26.8 vs. 8.8%). Differences in numbers of respiratory disorders mentioned appeared not to result from a tendency to hypochondria.

Adult↗
PubMed1995

Discrimination between panic disorder and generalized anxiety disorder by 35% carbon dioxide challenge.

OBJECTIVE: The authors' goal was to determine whether 35% carbon dioxide (CO2) challenge would discriminate between patients with panic disorder and patients with other anxiety disorders. METHOD: Nine patients with panic disorder and nine with generalized anxiety disorder underwent the 35% CO2 challenge. RESULTS: Patients with panic disorder experienced a significantly stronger increase in subjective anxiety than patients with generalized anxiety disorder. However, increases in panic symptom scores were high in both groups. CONCLUSIONS: These results suggest that a large increase in subjective anxiety due to the CO2 challenge is specific for patients with panic disorder but that an increase in panic symptoms is not.

Adult↗
PubMed1994

Yohimbine premedication and 35% CO2 vulnerability in healthy volunteers.

A group of 20 healthy volunteers underwent a 35% carbon dioxide/65% oxygen air-placebo controlled challenge test twice, premedicated 1 h before with either 20 mg yohimbine or placebo, following a double-blind randomized crossover design. Contrary to expectation the anxiety response to carbon dioxide was not higher when premedicated with yohimbine compared to premedication with placebo. Possible implications of this finding are discussed, with reference to general chemical models of panic.

Adolescent↗
PubMed1993

No chronic hyperventilation in panic disorder patients.

Arterial blood gases were measured and base excess calculated in 18 nonpanicking panic disorder (PD) patients, 12 subjects suffering from other anxiety disorders, and 18 normal control subjects. There was neither chronic nor clinically significant acute hyperventilation in either group.

Acid-Base Equilibrium↗
PubMed1991

Ventilatory response to CO2 in panic disorder.

The Read rebreathing technique was used to measure the ventilatory response to inhalation of carbon dioxide in 15 panic disorder patients, 15 obsessive-compulsive disorder patients, and 15 healthy control subjects. No significant differences in ventilatory response were found among the three groups. The tidal volume and frequency components of the ventilatory response also did not differ among the groups. The hypothetical pCO2 value corresponding with zero ventilation was significantly lower in the panic disorder patients than in normal control subjects.

Adult↗
PubMed1991

Attenuation of carbon dioxide-induced panic after clonazepam treatment.

Ten patients meeting the DSM-III-R criteria for panic disorder were treated with clonazepam. Prior to clonazepam treatment and after a 5-week treatment period, patients underwent a 35% carbon dioxide challenge procedure. Following clonazepam treatment, a significant reduction in carbon dioxide vulnerability was observed.

Adult↗
PubMed1991

Higher lifetime prevalence of respiratory diseases in panic disorder?

Current and past frequencies of respiratory diseases were assessed in 30 patients with panic disorder, 30 patients with obsessive-compulsive disorder, and 30 patients with eating disorders. Lifetime prevalence of respiratory disorders was significantly higher in patients with panic disorder (47%) than in patients with either obsessive-compulsive disorder (13%) or eating disorder (13%). Point prevalences showed no differences.

Adult↗
PubMed1991

Low doses of clonazepam in the treatment of panic disorder.

In order to assess the efficacy of a high-potency benzodiazepine in the treatment of panic disorder, an open trial was conducted with clonazepam. Clonazepam was administered in relatively low doses and, after four weeks, was shown to be effective in reducing the number of panic attacks and associated features of the disorder.

Adult↗
PubMed1990

Hypercarbia versus hypocarbia in panic disorder.

In order to compare the panicogenic effects of hypercarbia and hypocarbia in panic disorder (PD), 12 PD patients and 11 healthy controls underwent a 35% CO2 challenge as well as a hyperventilation provocation test in a random cross-over design. Both anxiety and anxiety symptoms proved to be significantly higher during the 35% CO2 challenge in PD patients as compared to the response during 35% CO2 in normals and during hyperventilation in both patients and normals. The results suggest that PD patients are specifically hypersensitive to an increase in pCO2.

Adolescent↗