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Biomedical subjects

K Howorka

Publications and source records attributed to K Howorka.

At least 19 recordsLinked to original sources
PubMed2000

Empowering diabetes out-patients with structured education: short-term and long-term effects of functional insulin treatment on perceived control over diabetes.

OBJECTIVE: To investigate short-term and long-term effects of structured outpatient education for Functional Insulin Treatment (FIT: selective insulin dosages for eating, fasting or correcting hyperglycaemia) on perceived control over diabetes and related health beliefs. FIT was thought to influence the perception of self-efficacy in diabetes, in contrast to conventional treatment, based on scheduled, rigid food intake and insulin delivery--it allows flexible eating, provided independent control of glycemia. METHODS: Structured, comprehensive, outpatient group training in FIT for selective use of insulin either for eating, fasting or correction included practical "insulin games." The FIT program focused on everyday criteria for choices of insulin dosages and thus on the patient's ability to execute his/her newly gained flexible treatment to his/her everyday life while preventing acute and late complications. To evaluate effects of FIT on "Perceived Control over Diabetes" and related "Health Beliefs Concerning Diabetes" (Bradley's questionnaires, 1984), a fully randomized short-term controlled Study 1 (four weeks, 32 patients), and long-term uncontrolled pilot Study 2 (three years, 68 patients) were performed. RESULTS: The short-term study revealed that FIT induced the feeling of independence from situational control while self-managing diabetes. In the long-term study, the patients were increasingly freed from the feeling of being under the control of physician and treatment-related restrictions, which--together with higher perceived self-efficacy--contributed to the feeling of "empowerment." This was associated with high treatment satisfaction and significant improvement of glycemic control. CONCLUSION: Structured out-patient group training for FIT results in measurable improvement of patients' perceived control over diabetes and self-efficacy.

Adolescent↗
PubMed2000

Decrease of vigilance assessed by EEG-mapping in type I diabetic patients with history of recurrent severe hypoglycaemia.

In Type I diabetic patients with history of recurrent severe hypoglycaemia, a more rapid decrease in vigilance (slowing of brain function) during hypoglycaemia in comparison to patients without history of such events was found. Our aims were: (1) to study EEG parameters of vigilance in non-hypoglycaemic state in representative groups of Type I diabetic patients with and without previous recurrent severe hypoglycaemia; and (2) to compare them with non-diabetic controls. A vigilance-controlled EEG mapping (10-20 system, significance probability maps) was performed in a non-hypoglycaemic state (blood glucose 4.0-10.0 mmol/l) in a group of 13 Type I diabetic patients with a history of recurrent severe hypoglycaemia and compared to that of 14 Type I diabetic patients without history of severe hypoglycaemia, matched for HbA1c, age and gender, and to age- and gender-matched non-diabetic controls. When compared to non-diabetic controls, hypoglycaemia patients demonstrated a reduction in absolute power in beta band (13-35 Hz) and slowing of centroid frequencies of beta and total frequency bands (1.3-35 Hz) (up to P < 0.01), whereas patients without history of severe hypoglycaemia showed only a borderline reduction of absolute power in delta (1.3-3.5 Hz) band. Deceleration in hypoglycaemia patients versus those without recurrent hypoglycaemia was most remarkable (P < .01) in centroid frequency of total frequency band. Patients with history of recurrent severe hypoglycaemia demonstrated in non-hypoglycaemic state significantly reduced vigilance when compared to the group without hypoglycaemia history and to the controls, as well. Lower vigilance may be at least in part responsible for impaired hypoglycaemia perception in these patients, but, as it resembles EEG patterns seen in pathologic ageing, it might also represent a consequence of recurrent episodes of severe hypoglycaemia.

Adult↗
PubMed2000

Dealing with ceiling baseline treatment satisfaction level in patients with diabetes under flexible, functional insulin treatment: assessment of improvements in treatment satisfaction with a new insulin analogue.

Even a small improvement in satisfaction with treatment for a chronic disease can be valuable. However, sensitive measurements instruments are needed to assess the effects of treatment changes in patients already well satisfied with baseline treatment. Such instruments were thought to be necessary to deal with ceiling effects in scores of satisfaction with functional insulin treatment (FIT) accommodating full flexibility of food intake and lifestyle in diabetes by manipulation of insulin (FIT; Howorka et al. 2000). The Status(S) version of the Diabetes Treatment Satisfaction Questionnaire (DTSQ, Bradley 1994) was extended with items measuring specific components of FIT and its psychometric properties investigated in a validation study with 171 FIT patients with diabetes. A new Change(C) version of DTSQ extended for FIT was used together with the DTSQ(S) by 52 participants in a subsequent randomised cross-over study involving new fast-acting lispro vs. regular insulin, where treatment satisfaction was the primary outcome variable. Insulin lispro use improved satisfaction (p < or = 0.001) both, on classical and extended versions of DTSQ(S) and (C), despite high baseline levels of satisfaction. However, the DTSQ(C) augmented the effects of lispro (p = 0.0001) apparent on DTSQ(S) scores and revealed significant treatment effects (p < or = 0.01) not significant with DTSQ(S). In parallel, glycaemic control improved with lispro (e.g., HbA1c, p = 0.023). Improved satisfaction with treatment was more apparent with DTSQ(C) than DTSQ(S) in patients who at baseline were at or near ceiling for treatment satisfaction.

Adult↗
PubMed1998

Optimal parameters of short-term heart rate spectrogram for routine evaluation of diabetic cardiovascular autonomic neuropathy.

Our aim was to select those parameters of heart rate variability (HRV) within its short-term power spectral analysis (PSA), which have a capability similar to that of the standard Ewing battery of cardiovascular function tests in determining different degrees of cardiovascular autonomic neuropathy (CAN) in diabetes and to compare the usefulness of both methods for diagnostic purposes in the everyday routine. Commonly used standard battery of cardiovascular autonomic function tests evaluated as total Ewing score as well as short-term PSA of HRV were used in 119 diabetic patients (age: 52.7 +/- 9.8, diabetes duration: 22.2 +/- 12.7 years). From this cohort, patients were selected according to the total Ewing score by matching for age, gender, BMI and diabetes type for 3 groups, each of 17 patients, with no CAN (total Ewing score 0-0.5), with early involvement (score 1.0-2.5) and with definite or severe CAN (score 3.0-5.0). Short-term PSA of HRV performed in three positions (supine1-standing-supine2) included frequency-domain and time-domain parameters of HRV. Cumulative spectral power of total frequency band (0.06-0.50 Hz) and spectral power of low-frequency band (0.06-0.15 Hz) during both supine positions proved to be the most selective and discriminating among all patient groups in inter-group comparison and in analysis of discriminance. The correlation between the total Ewing score and the cumulative spectral power of total frequency band was r = -0.87 (P < 0.001). About 83.2% of cases classified by short-term PSA of HRV using the variables selected by analysis of discriminance was congruent with the classification by the total Ewing score alone. Time expenditure for the performance of each examination was 31 +/- 10 min for Ewing test battery vs. 14 +/- 2 min for short-term PSA of HRV (P < 0.001). In summary, the latter method showed similar diagnostic value concerning the CAN as the classical Ewing standard battery of cardiovascular function tests, although its application proved to be shorter, less stressful and more independent from patient cooperation. Cumulative spectral power of total frequency band (LFHF cumpower) can be used for overall description of the degree of cardiac denervation in diabetes while using short-term PSA of HRV.

Adult↗
PubMed1998

Weak relationship between symptom perception and objective hypoglycaemia-induced changes of autonomic function in hypoglycaemia unawareness in diabetes.

To assess the relationship between symptom perception and neurophysiological characteristics in hypoglycaemia unawareness, we investigated the awareness of symptoms, objective changes of autonomic function and counter-regulatory neuroendocrine responses to hypoglycaemia in intensively treated type I (insulin-dependent) diabetic patients with different degrees of hypoglycaemia unawareness. Hypoglycaemia (venous plasma glucose below 2.2 mmol/l) was induced with an intravenous insulin bolus in subjects with a history of repeated severe hypoglycaemia and hypoglycaemia unawareness (n = 10) and in a comparable group with good awareness of hypoglycaemia (n = 8). Autonomic symptoms, selected parameters of autonomic function and counter-regulatory hormones were assessed serially. Although hypoglycaemia was more pronounced in unaware patients (1.6 vs 2.0 mmol/l, P = 0.05), their induced adrenaline response was markedly impaired (delta adrenaline: 1.25+/-1.10 vs 2.55+/-1.46 nmol/l, P = 0.05). Astonishingly, differences between both patient groups in the course of autonomic function changes did not reach the level of significance (P = 0.35-0.92), although the unaware group reported markedly fewer autonomic symptoms, both neurogenic (P = 0.001) and neuroglycopenic (P = 0.04) than the aware group. This study indicates that in hypoglycaemia unawareness even extensive changes in autonomic function are not sufficient for the perception of hypoglycaemia and confirms that the central nervous system plays an important role in the awareness of hypoglycaemia.

Adult↗
PubMed1997

Effects of physical training on heart rate variability in diabetic patients with various degrees of cardiovascular autonomic neuropathy.

OBJECTIVE: To investigate the effects of regularly performed endurance training on heart rate variability in diabetic patients with different degrees of cardiovascular autonomic neuropathy (CAN). METHODS: Bicycle ergometer training (12 weeks, 2 x 30 min/week, with 65% of maximal performance) was performed by 22 insulin-requiring diabetic patients (age 49.5 +/- 8.7 years; diabetes duration 18.6 +/- 10.6 years; BMI 25.1 +/- 3.4 kg/m2): i.e., by 8 subjects with no CAN, 8 with early CAN and by 6 patients with definite/severe CAN. A standard battery of cardiovascular reflex tests was used for grading of CAN, a short-term spectral analysis of heart rate variability for follow-up monitoring of training-induced effects. RESULTS: While the training-free interval induced no changes in spectral indices, the 12-week training period increased the cumulative spectral power of the total frequency band (P = 0.04) but to a different extent (P = 0.039) in different degrees of neuropathy. In patients with no CAN the spectral power in the high-frequency (HF) band (0.15-0.50 Hz) increased from 6.2 +/- 0.3 to 6.6 +/- 0.4 In [ms2]; P = 0.016, and in the low-frequency (LF) band (0.06-0.13 Hz) from 7.1 +/- 0.1 to 7.6 +/- 0.3 in [ms2]; P = 0.08 which resulted in an increase of total spectral power (0.06-0.50 Hz) from 7.5 +/- 0.1 to 8.0 +/- 0.3 in [ms2] (P = 0.05). Patients with the early form of CAN showed an increase of spectral power in HF (5.1 +/- 0.2 to 5.8 +/- 0.1 in [ms2], P = 0.05) and LF bands (5.6 +/- 0.1 to 6.3 +/- 0.1 in [ms2], P = 0.008), resulting in an increase of total power from 6.1 +/- 0.1 to 6.6 +/- 0.1 in [ms2] (P = 0.04), whereas those with definite/severe CAN showed no changes after the training period. Training improved fitness in the whole patient cohort. The increased autonomic tone as assessed by spectral indices disappeared after a training withdrawal period of 6 weeks. CONCLUSIONS: In diabetic patients with no or early CAN, regularly performed endurance training increased heart rate variability due to improved sympathetic and parasympathetic supply, whereas in subjects with definite/severe CAN no effect on heart rate variability could be demonstrated after this kind of training.

Autonomic Nervous System Diseases↗
PubMed1996

Monitoring set-up for selection of parameters for detection of hypoglycaemia in diabetic patients.

Recurrent severe hypoglycaemia is often an unsolved problem in diabetic patients under intensified insulin treatment. As no reliable long-term stable blood glucose sensor has yet been developed, registration of other body function changes could help to detect severe hypoglycaemia. A measuring system is described, capable on the one hand of recording EEG, heart rate, peripheral pulse, skin temperature, respiratory movements, skin impedance and arterial blood pressure, and capable of registering plasma glucose, counter-regulatory hormones, symptoms and cognitive performance under experimental conditions during hypoglycaemia, on the other. In a clinical study involving both insulin-induced hypoglycaemia in healthy subjects and insulin-dependent diabetic patients, the practical value and the character of changes of the recorded parameters are investigated. Currently insensitivity to hypoglycaemia, impracticability, complexity or susceptibility to artefacts make use of most parameters unsuitable for hypoglycaemia prevention. It is believed, however, that future efforts could result in indirect registration of hypoglycaemia, including a qualified combination of different parameters, individual adaptation in accordance with particular responses of individual patients, together with new measuring and sensor techniques.

Adult↗
PubMed1996

Severe hypoglycaemia unawareness is associated with an early decrease in vigilance during hypoglycaemia.

To elucidate neurophysiological characteristics in hypoglycaemia unawareness, we investigated the relationship between electroencephalography (EEG) parameters of vigilance and awareness of various symptom categories early in response to hypoglycaemia in intensively treated diabetic patients with different degrees of hypoglycaemia unawareness. Hypoglycaemia (venous plasma glucose below 2.2 mmol/1) was induced with an intravenous insulin bolus in seven patients with insulin-dependent diabetes mellitus (IDDM) with a history of hypoglycaemia unawareness and repeated severe hypoglycaemia, as well as in a group of seven IDDM patients with good awareness of hypoglycaemia. Both groups were comparable in age, treatment strategy, glycaemic control and level of late complications. Basic cognitive performance and other symptom categories were estimated serially during a period of 2 h following the insulin bolus. A vigilance-controlled EEG was recorded continuously; its automatic analysis included the evaluation of vigilance indices. In the baseline prehypoglycaemic state, hypoglycaemia unaware patients showed higher initial vigilance (p = .05) than the aware group. Unaware patients reported fewer neurogenic (p = .002, mainly cholinergic, p = .009) hypoglycaemia symptoms during hypoglycaemia, and developed an impairment in cognitive performance over time (p = .002). EEG analysis indicated a more rapid decrease in vigilance after the hypoglycaemic stimulus for unaware patients than for aware patients. The lowering of plasma glucose to 3.06-3.89 mmol/l already induced a significant increase in delta and theta, as well as a decrease in alpha relative power only in the unaware group. Differences between groups with regards to the degree of deceleration were most pronounced early, during only slight hypoglycaemia, and topographically spread over central and parietal brain regions. Further lowering of plasma glucose induced an even more pronounced, abrupt increase in slow waves in unaware patients at higher plasma glucose levels than in hypoglycaemia aware subjects (for delta waves at 2.41 +/- 0.16 vs. 1.96 +/- 0.1 mmol/l, p = .04). This preceded the worsening of cognitive performance during hypoglycaemia in unaware patients by 19 +/- 3 min. Hypoglycaemia unawareness associated with previous unconsciousness is associated with- and may be the result of-an early hypoglycaemia-induced reduction in vigilance and an early EEG deceleration, which seems to be a teleologically effective measure for delaying eventual cerebral energy failure in hypoglycaemia.

Adult↗
PubMed1996

[Modular education in diabetes and pregnancy: analysis of results of 58 pregnancies in diabetic patients with functional insulin treatment].

Functional insulin treatment based on the patient's education for selective use of insulin for fasting, eating or correction of hyperglycaemia was used between 1985 and 1994 prospectively in 58 pregnancies (in 18 cases after conception) in 47 pregnant diabetic patients. We hypothesised that near-normalisation of glycaemia is possible throughout pregnancy by modular outpatient group education, individual counselling and functional insulin treatment. We wanted to investigate to which degree it might eliminate classical diabetes-associated neonatal complications. To avoid hospitalisation if possible and premature induction of labour, patients were taught both the primary adjustment (immediate correction of hyperglycaemia) and the secondary adjustment of the insulin dosages: correction of individual algorithms for insulin use according to daily insulin consumption and mean blood glucose MBG. A target metabolic control (HbA1c levels in the normal range, MBG < 100 and < 90 mg/dl after the 28th week of gestation respectively) was achieved in the majority of the 58 pregnancies. Severe hypoglycaemia occurred in 12 patients (21%). The gestational age at delivery was 39.0 +/- 1.6 (34-41; in 3 cases only [5%] < 37) weeks with an average birth weight of 3335 +/- 521 (1950-4450) g. The birth weight of only 5 newborn (9%) was above the 90th percentile and no one below the 10th percentile for weight of a comparable population. No cases of respiratory distress were observed. Hypoglycaemia was recorded in only 4 newborn (7%) and was comparable also to that of offsprings in non-diabetic women. Malformations were found in two offsprings whose mothers had presented first for diabetes education after conception, pregnancy being terminated in one case of meningomyelocele. Caesarean section (n = 15; 26%) was primarily due to maternal reasons. Functional insulin treatment prior to conception, modular diabetes group education, specific patient motivation for a near-normal glycaemia throughout pregnancy as well as interdisciplinary care allow pregnancy outcome in diabetic patients similar to that in non-diabetic women and thus the realisation of the 5-year targets of the WHO Declaration of St. Vincent 1989.

Adolescent↗
PubMed1996

EEG topography during insulin-induced hypoglycemia in patients with insulin-dependent diabetes mellitus.

A group of young patients with insulin-dependent diabetes mellitus (n = 14; 8 men, 6 women; 33.1 +/- 8.9 years) were examined by topographic EEG mapping under normoglycemic and hypoglycemic conditions (glucose levels after intravenous insulin injection down to 32.6 +/- 7.6 mg/dl). From the clinical aspect, 7 of them had a good and 7 had a poor awareness of hypoglycemia. During hypoglycemia, a decrease in alpha activity (p < 0.05), an increase in delta (p < 0.05), and especially in theta activity (p < 0.05) were found. The most sensitive parameter was the alpha/theta ratio. In the range of slight hypoglycemia (50-60 mg/dl) the increase in delta and theta activity showed a topographic maximum in lateral frontal regions. During deep hypoglycemia there was a topographic maximum of slow frequencies in posterior parts of the brain (centrotemporal to parieto-occipital regions). The differences between the group with good and with poor awareness of hypoglycemia were most pronounced during slight hypoglycemia in C3, C4, and Pz (p < 0.05). At lower glucose levels group distinction was no longer possible. These EEG changes correspond to a temporary organic brain syndrome.

Adult↗
PubMed1994

Feasibility and efficacy of intensive insulin therapy in type 1 diabetes mellitus in primary care.

To determine the feasibility and efficacy of structured education in intensive insulin therapy (IIT) in patients with Type 1 diabetes mellitus commonly attended by primary care physicians, a prospective case-control study was carried out in co-operation with 26 general practitioners in rural Alpine region and the diabetes service at the University of Vienna, Medical School, Austria. From 89 rural Type 1 diabetic patients on conventional insulin therapy (CIT), those volunteering for better diabetes care (n = 52) were trained in IIT in the diabetes education centre and subsequently received their outpatient service by their general practitioners, as did those remaining on CIT (n = 37). Patients were matched as case-controls (n = 36 in each therapy group) for metabolic control at baseline (IIT/CIT: HbA1c 8.2 +/- 1.8 vs 8.1 +/- 2.0%, ns), age, duration of diabetes, incidence of retinopathy and nephropathy. Analysing an observation period of > 4.5 years, patients trained in IIT presented with improved metabolic control as compared to those on CIT (Mean HbA1c: IIT, 6.9 +/- 1.0%; CIT, 7.9 +/- 1.3%, p < 0.05, ANOVA). No difference between groups was, however, observed at the end-point of the study in HbA1c (IIT, 7.3 +/- 1.3%; CIT, 7.8 +/- 1.4%; IIT vs CIT, p = 0.14) and in the development of diabetic microangiopathy, frequency of reported severe hypoglycaemic episodes, and increase in body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Conventional or functional insulin therapy?].

The main difference between "conventional" and "functional" insulin replacement is that the former requires meals to be taken at set times throughout the day to avoid hypoglycaemic insulin reactions, while the latter separates insulin replacement in the basal ("fasting") state from that required with food intake. Such strategy reverses conventional insulin treatment (namely balancing the action of administered insulin by a fixed dietary intake), by substitution with a functional control of hyperglycaemia on the basis of tailored insulin doses. To this end blood glucose self control and systemic blood glucose correction are a must during functional insulin substitution, but not necessarily so during conventional insulin therapy. From this it is apparent that "conventional" and "functional" insulin therapy refer to different strategies, both of which may be intensified by more strict rules, although the term "intensified" remains without any conceptional meaning per se. However, whatever the therapeutic recommendation, the attending physician has to be aware that he must appropriately inform and train the insulin-deficient patient (a) on how to deal with a proposed treatment schedule, and (b) to the point that he fully understands the available therapeutic possibilities and the difference in their quality. Experience has shown that a majority of informed patients opt for functional therapy.

Blood Glucose↗
PubMed1987

[Type I diabetes mellitus and pregnancy: an interdisciplinary management program].

The obstetrical management of pregnant women with pregestational diabetes has been significantly improved throughout recent years. In the past, efforts to maintain euglycaemia during pregnancy in the presence of a labile maternal metabolism led to repeated, long-term hospitalization. In an interdisciplinary joint effort a protocol was delineated to obtain euglycemia throughout pregnancy by functional insulin therapy aiming at "near-normoglycemic insulin substitution (NIS)". In order to achieve this goal, home glucose monitoring and, depending on the glucose levels, self-made adjustments to the insulin therapy (according to individual algorithm) are the essential parts of this protocol. Of our study group of 18 pregnant diabetic women, already eight of them (2 class B, 1 class C, 1 class D, 2 class R and 2 class RF) have been delivered. The mean maternal age was 27 years (21-39). All metabolic variables of consequence for a diabetic woman were within the normal limits. The mothers' mean weight gain was 16 kg (12-20), and the mean gestational age at delivery was 37.8 weeks (35-40). The mean birth weight was 3293 grams (2700-3700) and all newborns were within the 50th percentile. Five fetuses were delivered by caesarian section (indications: proliferative retinopathy 3, breech presentation 1, previous caesarian section 1). No congenital malformations were found, nor macrosomia, respiratory distress syndrome or postpartum hyperglycaemia in the newborn. These preliminary results are encouraging. We feel that functional insulin therapy aiming at "near-normoglycaemic insulin substitution" promises to be very effective for women who are able and willing to follow the instructions received in the special education program.

Adult↗