Proton magnetic resonance spectroscopy of human amniotic fluids sampled at 17-18 weeks of pregnancy in cases of decreased digestive enzyme activities and detected cystic fibrosis

Low digestive enzyme activities in human amniotic fluid can be observed in normal and disease-affected pregnancies: cystic fibrosis, trisomy 21, intestinal atresia. Amniotic fluids were analyzed by proton nuclear magnetic resonance (NMR) spectroscopy in order to specify prenatally the etiology of low digestive enzyme activities observed at 17-18 weeks of amenorrhea. A total of 114 amniotic fluid samples were collected at 17-18 weeks of amenorrhea. Karyotyping and assays of digestive enzyme activities were performed in all cases. Samples were divided into six groups according to enzyme activities and pathology. Proton spectra were retrospectively recorded. Many compounds, such as amino acids and carboxylic acids, were detected by NMR. The same resonance intensities (normalized to creatinine) were observed in the six groups. Nevertheless, an unidentified resonance at 1.05 ppm was detected in seven out of 13 cases of cystic fibrosis affected fetuses. The NMR spectra demonstrated the stability of the amniotic fluid composition at 17-18 weeks of amenorrhea, even when the fetus was affected by a disease such as trisomy 21 or intestinal atresia. The resonance associated with most cases of cystic fibrosis should be further investigated.

Relationship between sleep stages and metabolic rate in humans

Differences in sleeping metabolic rate (SMR) among subjects may be related to different levels of energy expenditure associated with sleep stages. The relationship between energy expenditure and sleep stages was investigated overnight in 29 subjects (14 Caucasians and 15 Pima Indians, 18 males and 11 females; mean +/- SD, 31 +/- 7 yr, 83 +/- 26 kg, 27 +/- 11% fat). Sleep stages were determined by electroencephalogram recording, whereas energy expenditure was measured in a 1,000-liter Plexiglas sleep box constructed around a bed as a fast-response open-circuit indirect calorimeter. Eighty-five percent of the interindividual variability in SMR was explained by differences in fat-free mass, fat mass, age, sex, and race (r2 = 0.85). The intra-individual variance in SMR over time was related to sleep stages and to clock time. Within subjects, SMR in stage 3 was significantly lower than in stage 2 (-39 +/- 18 kcal/day; P < 0.05) and rapid eye movement sleep (-51 +/- 23 kcal/day; P < 0.05). Also, sleep stages were associated with different respiratory quotients. Because sleep stages are associated with only small differences in energy metabolism, our results suggest that sleep stages play a minor role in the variance of SMR among subjects. However, the duration of sleep may contribute to the variability of 24-h energy expenditure.

Evaluation of liquid chromatography coupled with high-field 1H NMR spectroscopy for drug metabolite detection and characterization: the identification of paracetamol metabolites in urine and bile

The applicability of coupled reversed-phase high performance liquid chromatography (HPLC)-NMR spectroscopy for the detection and identification of paracetamol (N-(4-hydroxyphenyl)acetamide) and its sulfate, glucuronide and N-acetylcysteinyl metabolites in the unprocessed biological fluids, human urine, rat urine and rat bile, is investigated. Analysis of these samples was performed by gradient HPLC elution and directly coupled 500 MHz 1H NMR spectroscopy detection using a combination of one- and two-dimensional NMR methods in stopped-flow mode. The stopped-flow approach is demonstrated to be an efficient technique for identification of drug metabolites which have, for example, a UV-chromophore. Stopped-flow HPLC analysis with NMR detection is a viable technique and halting the chromatographic process several times during a run has a negligible effect on the separation and NMR characterization. The post-acquisition data processing method of 'quantified maximum entropy' is shown to provide a means of improving the quality of spectra for minor components, thus aiding NMR resonance assignments.

Automatic reduction of NMR spectroscopic data for statistical and pattern recognition classification of samples

A general method of automatically reducing NMR spectra to provide numerical descriptors of samples has been developed and investigated. These descriptors can be used as input to pattern recognition or multivariate algorithms for sample classification. The methods have been tested using 600 MHz one-dimensional 1H NMR spectra of biofluids which are complex mixtures. The approach is, in principle, applicable to multidimensional and heteronuclear NMR spectra and to other types of liquid samples such as oils and foodstuffs as well as to situations such as 1H or 31P NMR in vivo and solid state NMR in drug formulation analysis. The method relies upon apportioning the information in the spectra to individual contiguous segments and allowing specified regions of the spectra to be omitted. Three approaches, based on the number of peaks, the summed peak heights and the summed peak areas respectively in each segment, have been tested. The effect of segment width and overlap and the effects of manipulation of the NMR spectra have been evaluated in terms of the classification of the samples using principal components analysis. A simple method of generating NMR based spectral descriptors for object classification is thus proposed.

Automatic data reduction and pattern recognition methods for analysis of 1H nuclear magnetic resonance spectra of human urine from normal and pathological states

Multivariate data analysis techniques have been used to compare 600-MHz 1H nuclear magnetic resonance (NMR) spectra of urine obtained from patients with inborn errors of metabolism (IEM) and urine obtained from healthy subjects. These spectra are very complex; each contains many thousands of resonances with a high dynamic range. A consistent method of reducing this wealth of data to manageable proportions is presented as a two-stage process. Computer-based spectral descriptors are automatically generated and then reduced to two-dimensional maps for visualization of clustering. Data-scaling methodology has been developed to achieve complete separation between spectra from control adults and those from adult patients with independently diagnosed IEM. The methods were refined by relating IEM samples to the mean of the control samples and applying supervised learning techniques to identify descriptors contributing to class separation. This approach allowed separation of the various classes of IEM and achieved optimal separation of patients with cystinuria from those with oxalic aciduria; the principal metabolites responsible for this separation were determined as lysine and glyoxalate. The methods developed were then extended by application to the more subtle problem of classifying urine collected from healthy subjects under different physiological conditions (i.e., pre- and post-exercise and in different stages of hydration) where, unlike the IEM case, any underlying biochemical differences were not known at the outset. Fluid-loaded and fluid-deprived samples could be partially separated as well as fluid-deprived and fluid-restored samples. Partial classification of samples on the basis of subject was also observed. Therefore, intersubject differences were liable to obscure the separation by physiological state. However, by relating each sample to a mean of the normal daily urine samples for the same person and applying a form of "range scaling" to exclude data which contributed least to class separation, improved classification of the hydration states resulted, from which it was possible to deduce those biochemical substances which were altered. These novel techniques for the data reduction and classification of NMR spectra make comprehensive use of all of the NMR spectral information and have clear potential to assist in clinical diagnosis.

Application of the one-dimensional TOCSY pulse sequence in 750 MHz 1H-NMR spectroscopy for assignment of endogenous metabolite resonances in biofluids

The complex 1H-NMR spectrum arising from an intact biofluid has been simplified using a one-dimensional homonuclear polarization transfer experiment (known as TOCSY or HOHAHA). This approach establishes connectivity between sequentially coupled multiplets, and the method is illustrated by the confirmation of the chemical shifts and hence resonance assignment of a number of endogenous metabolites in the 750 MHz 1H-NMR spectrum of seminal fluid. This has allowed the detection and assignment of pyroglutamate and uracil in this fluid for the first time.

Determinants of total daily energy expenditure: variability in physical activity

Excessive energy intake and/or reduced total daily energy expenditure (TEE) causes obesity. To determine the relationship between obesity and TEE in an obesity-prone population, we measured TEE, 24-h sedentary energy expenditure (SEDEE), and basal metabolic rate (BMR) in 30 Pima Indian men (83.6 +/- 20.0 kg and 31 +/- 9% fat) by the doubly labeled water method and a respiratory chamber. The energy expenditure for physical activity (EEACT) was calculated as TEE - (BMR + 0.1 TEE), where 10% of TEE is an estimate of the thermic effect of food. Fat-free mass was the best single determinant (P < 0.01) of TEE, explaining 48% of its variance. TEE, SEDEE, BMR, and EEACT were 12,010 +/- 2292, 9945 +/- 1559, 7677 +/- 1901, and 3297 +/- 1732 kJ/d, respectively. Because EEACT is dependent on body weight, EEACT/kg body wt (41.7 +/- 23.2 kJ.d-1.kg-1) and TEE/(BMR + 0.1 TEE) (1.39 +/- 0.22) were used as indexes of the level of physical activity. Both indexes correlated negatively with percent body fat (r = -0.56, P < 0.01 and r = -0.42, P < 0.03, respectively). These results suggest that obesity is associated with lower levels of physical activity.

Muscle sympathetic nerve activity in response to glucose ingestion. Impact of plasma insulin and body fat

Carbohydrate intake stimulates sympathetic nervous system activity in lean subjects, whereas in obese subjects, the results have been inconsistent. The aim of this study was to directly measure sympathetic neural outflow to skeletal muscle in response to a 75-g oral glucose tolerance test (OGTT) in 15 Pima Indian and 16 Caucasian men, matched for body fat and age, but covering a large range of body weight (57-113 kg) and body fat (4-41%). Fasting muscle sympathetic nerve activity (MSNA) correlated positively with body fat (r = 0.73; P = 0.001) in Caucasians but not in Pima Indians, whereas the increase in MSNA during the OGTT correlated negatively with the percentage of body fat (r = -0.38, P = 0.03) independently of race. In each subject, the increase in MSNA over time correlated positively with the increase in plasma insulin levels, but the slopes of these relationships were inversely related to the percentage of body fat (r = -0.52, P = 0.003) independently of race. In conclusion, obesity is associated with a higher fasting sympathetic neural outflow to muscle but a blunted increase in response to an oral glucose load despite a larger increase in plasma insulin levels. This blunted response may represent another feature of the obesity/insulin resistance syndrome.

Ultra high field NMR spectroscopic studies on human seminal fluid, seminal vesicle and prostatic secretions

Ultra high field 1H-NMR spectroscopic methods have been used to analyse the composition of seminal fluid and its component secretions, prostatic and seminal vesicle fluids from normal human subjects and those with vasal aplasia and non-obstructive infertility. The 1H-NMR spectrum of whole seminal fluid is extremely complex and many resonances are extensively overlapped in single pulse spectra even when measured at 600 or 750 MHz 1H resonance frequency. A combination of 2-D 1H-NMR methods (including J-Resolved and various 1H homonuclear correlation and 1H-13C heteronuclear correlation techniques) were applied at 600 or 750 MHz in order to extensively assign the signals from the organic components of seminal fluid. Prostatic fluid (PF) gives a much less complex metabolite profile than whole seminal fluid and can be completely analysed using 500 MHz 1H-NMR spectroscopy. The 1H-NMR spectra of prostatic fluid are dominated by signals from citrate, spermine and myo-inositol, whereas the spectra of seminal vesicle fluid (SVF) show extensively overlapped signals from complex peptide mixtures together with strong signals for glycerophosphocholine (GPC) and lactate. Whole seminal fluid is a combination of the PF and SVF constituents together with further substances that appear after mixing due to the operation of PF enzymes on SVF, e.g. peptidase activity causes rapid cleavage of peptides to amino acids and GPC is hydrolysed to choline, glycerol and inorganic phosphate. It is also shown that vasal aplasia leads to highly characteristic abnormal metabolite profiles in seminal fluid that can be readily observed in single-pulse 500 and 600 MHz 1H-NMR spectra. Measurement of the molar citrate to choline, or spermine to choline ratios in seminal fluid both show differences of 2 orders of magnitude between vasal aplasia (greater for both ratios) and non-obstructed infertile patients. This work gives an indication of the potential of high field 1H-NMR spectroscopy in the investigation and assessment of the secretory functions of the male genital tract and the evaluation of the infertile male subject.

Insulin resistance and insulin secretory dysfunction as precursors of non-insulin-dependent diabetes mellitus. Prospective studies of Pima Indians

BACKGROUND

The relative roles of obesity, insulin resistance, insulin secretory dysfunction, and excess hepatic glucose production in the development of non-insulin-dependent diabetes mellitus (NIDDM) are controversial. We conducted a prospective study to determine which of these factors predicted the development of the disease in a group of Pima Indians.

METHODS

A body-composition assessment, oral and intravenous glucose-tolerance tests, and a hyperinsulinemic--euglycemic clamp study were performed in 200 non-diabetic Pima Indians (87 women and 113 men; mean [+/- SD] age, 26 +/- 6 years). The subjects were followed yearly thereafter for an average of 5.3 years.

RESULTS

Diabetes developed in 38 subjects during follow-up. Obesity, insulin resistance (independent of obesity), and low acute plasma insulin response to intravenous glucose (with the degree of obesity and insulin resistance taken into account) were predictors of NIDDM: The six-year cumulative incidence of NIDDM was 39 percent in persons with values below the median for both insulin action and acute insulin response, 27 percent in those with values below the median for insulin action but above that for acute insulin response, 13 percent in those with values above the median for insulin action and below that for acute insulin response, and 0 in those with values originally above the median for both characteristics.

CONCLUSIONS

Insulin resistance is a major risk factor for the development of NIDDM: A low acute insulin response to glucose is an additional but weaker risk factor.

Metabolism of benzbromarone in man: structures of new oxidative metabolites, 6-hydroxy- and 1'-oxo-benzbromarone, and the enantioselective formation and elimination of 1'-hydroxybenzbromarone

1. The uricosuric drug benzbromarone is extensively metabolized in man and two main metabolites are formed: the previously characterized 1'-hydroxybenzbromarone (metabolite M1) and an arylhydroxybenzbromarone (metabolite M2) of unknown structure. A dimethyl derivative was isolated from urine after methylation and was characterized by gas chromatography-mass spectrometry (g.l.c.-m.s.) and high resolution nuclear magnetic resonance spectroscopy as 4''-O-methyl-6-methoxybenzbromarone; the structure of M2 therefore is 6-hydroxybenzbromarone. 2. A minor metabolite was similarly characterized as 1'-oxobenzbromarone by comparison with authentic synthetic samples and is a product of biodegradation and not an artifact derived from the in vitro oxidation of 1'-hydroxybenzbromarone. Further minor metabolites were detected and were provisionally characterized by g.l.c.-m.s. after derivatization and include: 2'-hydroxybenzbromarone (an isomer of 1'-hydroxybenzbromarone); 1',6-dihydroxybenzbromarone; dihydroxy-aryl-benzbromarone; and two structure isomers of 6-hydroxybenzbromarone. Debrominated metabolites were not detectable. 3. Benzbromarone is hydroxylated in vivo at the prochiral centre C1' to 1'-hydroxybenzbromarone; analysis of 1'-hydroxybenzbromarone from plasma and urine extracts by h.p.l.c. using a chiral column revealed that two peaks were eluted which showed a mean enantiomeric ratio of 2.1 for plasma and 7.3 for urine; these data demonstrate that the formation and elimination of this metabolite is enantioselective; the absolute configuration of the 1'-chiral centre is presently unknown.

Reduced sympathetic nervous activity. A potential mechanism predisposing to body weight gain

The sympathetic nervous system is recognized to play a role in the etiology of animal and possibly human obesity through its impact on energy expenditure and/or food intake. We, therefore, measured fasting muscle sympathetic nerve activity (MSNA) in the peroneal nerve and its relationship with energy expenditure and body composition in 25 relatively lean Pima Indian males (means +/- SD; 26 +/- 6 yr, 82 +/- 19 kg, 28 +/- 10% body fat) and 19 Caucasian males (29 +/- 5 yr, 81 +/- 13 kg, 24 +/- 9% body fat). 24-h energy expenditure, sleeping metabolic rate, and resting metabolic rate were measured in a respiratory chamber, whereas body composition was estimated by hydrodensitometry. Pima Indians had lower MSNA than Caucasians (23 +/- 6 vs 33 +/- 10 bursts/min, P = 0.0007). MSNA was significantly related to percent body fat in Caucasians (r = 0.55, P = 0.01) but not in Pimas. MSNA also correlated with energy expenditure adjusted for fat-free mass, fat mass, and age in Caucasians (r = 0.51, P = 0.03; r = 0.54, P = 0.02; and r = 0.53, P = 0.02 for adjusted 24-h energy expenditure, sleeping metabolic rate, and resting metabolic rate, respectively) but not in Pima Indians. In conclusion, the activity of the sympathetic nervous system is a determinant of energy expenditure in Caucasians. Individuals with low resting MSNA may be at risk for body weight gain resulting from a lower metabolic rate. A low resting MSNA and the lack of impact of MSNA on metabolic rate might play a role in the etiology of obesity in Pima Indians.

Coupling of HPLC with 19F- and 1H-NMR spectroscopy to investigate the human urinary excretion of flurbiprofen metabolites

Results of an on-line HPLC-NMR analysis of human urine from a volunteer administered the anti-inflammatory drug flurbiprofen are reported. The two major human urinary metabolites, namely the glucuronides of flurbiprofen and of 4'-hydroxyflurbiprofen, have been identified using 1H- and 19F-NMR spectroscopy. In vivo conjugation of the racemic drug and its metabolites with D-glucuronic acid results in diastereomeric molecules which give resolved NMR spectra thereby permitting the diastereomeric proportions to be evaluated. The cause of the observed deviation from equal proportions is discussed. This study represents the first use of both 19F- and 600 MHz 1H-NMR spectroscopy coupled to HPLC.

Investigation of the human metabolism of antipyrine using coupled liquid chromatography and nuclear magnetic resonance spectroscopy of urine

The potential of coupled high-performance liquid chromatography-nuclear magnetic resonance spectroscopy for the detection and identification of drug metabolites has been investigated by direct analysis of human urine collected following administration of antipyrine. This approach provided a rapid method of characterizing the major human urinary metabolites of this drug and promises to be of widespread value in structural studies of xenobiotic metabolites.

Daily energy expenditure by five-year-old children, measured by doubly labeled water

Current recommendations for daily energy requirements in 5-year-old children (90 kcal/kg per day) are based on energy intake associated with normal growth. It is not known, however, how these recommendations compare with total free-living energy expenditure (TEE) and how much of TEE is related to physical activity. The TEE and the resting metabolic rate (RMR) were measured in 28 white children, aged 5 years (15 boys, 13 girls; mean (+/- SD) weight 20.1 +/- 3.4 kg; height 113 +/- 6 cm; fat 20% +/- 5%). The TEE was calculated during a 7-day period from urinary elimination rates of deuterium (2H) and heavy oxygen (18O) by using a modification of the two-point slope-intercept method; RMR was measured by a ventilated-hood indirect calorimeter. Physical activity indexes were also collected from questionnaires completed by the parents. Measured TEE was considerably lower than the recommended dietary allowances (1370 +/- 222 kcal/day vs 1807 +/- 310 kcal/day; p < 0.0001), whereas measured RMR was slightly higher than predicted RMR (1001 +/- 119 kcal/day vs 952 +/- 78 kcal/day; p < 0.001). The energy cost of physical activity accounted for only 16% +/- 7% of TEE. An index of activity, assessed as the difference between the measured TEE and the predicted TEE, correlated positively with past-year sport-leisure activity assessed by questionnaire (r = 0.40; p < 0.05). We conclude that measured TEE in 5-year-old children yields lower values (approximately 400 kcal/day) than current estimates. A minute part of this difference (20 to 30 kcal/day) is related to the changes in energy stores during growth, but most seems due to lower-than-expected levels of physical activity. This might be related to increased television viewing, which replaces activities requiring energy.

750 MHz 1H-NMR spectroscopy of human blood plasma

The application of high-resolution 750 MHz 1H-NMR spectroscopy to a biological fluid is demonstrated for the first time and its advantages over 600 MHz 1H observation shown by reference to studies on human blood plasma. Improvements in signal dispersion were observed which facilitated improved signal assignments. Differences in lipid/lipoprotein signal line-widths between 600 and 750 MHz were noted indicating that ultrahigh field measurements may help to give insight into dynamic motional phenomena of lipids in whole plasma. The two-dimensional J-resolved (JRES) technique and spin-echo spectra measured at 750 MHz have enabled new signal assignments to be made in control plasma. The application of 750 MHz JRES to the clinical chemical problem of the detection of abnormal metabolites associated with chronic renal failure is also demonstrated.

Linkage of chromosomal markers on 4q with a putative gene determining maximal insulin action in Pima Indians

Insulin action in vivo varies widely in nondiabetic Pima Indians. Not all of this variance is attributable to individual differences in obesity, physical fitness, sex, or age, and after correcting for these co-variates, measures of insulin action aggregate in families. Insulin action at maximally stimulating insulin concentrations has a trimodal frequency distribution, particularly among obese individuals. This is consistent with the hypothesis that a codominantly inherited autosomal gene, unrelated to obesity, determines MaxM in the population. Preliminary sib-pair linkage analyses indicated the possibility of linkage between MaxM and the GYPA/B locus (encoding the MNSs red cell surface antigens) on chromosome 4q. To confirm and extend these findings, 10 additional loci on 4q were typed in 123 siblings and many of their parents from 46 nuclear families. The results indicate significant (P < 0.001) linkage of the FABP2 and ANX5 loci on 4q with MaxM, and of FABP2 with fasting insulin concentration. No linkage was found between the 4q markers and obesity. Our findings indicate that a gene on 4q, near the FABP2 and ANX5 loci, contributes to in vivo insulin action in Pima Indians.

High-performance liquid chromatography coupled to high-field proton nuclear magnetic resonance spectroscopy: application to the urinary metabolites of ibuprofen

The use of coupled reversed-phase high-performance liquid chromatography and high-field proton nuclear magnetic resonance spectroscopy (HPLC-NMR) for the detection and identification of the urinary metabolites of ibuprofen is described. Urine was obtained from a healthy human volunteer following a normal therapeutic dose of 400 mg of ibuprofen. Analysis was performed on both a freeze-dried urine concentrate and partially purified extracts obtained by solid-phase extraction onto C-18 bonded silica gel. Both continuous and stop-flow methods were used to obtain spectra enabling the major urinary metabolites of ibuprofen to be detected and identified.

How effective is cushioned therapeutic footwear in protecting diabetic feet? A clinical study

Therapeutic footwear with cushioned insoles was supplied to 50 diabetic patients with severe peripheral neuropathy and/or peripheral vascular disease (age 59(SD 12) years, known duration of diabetes 17(7) years), 36 of whom had a history of foot ulceration. A follow-up examination was carried out 25(14) months later, except in 8 patients who died from conditions unrelated to their foot lesions, and 1 patient who died from sepsis due to upper limb amputation. Among the surviving 41 patients, intercurrent foot lesions during follow-up occurred in significantly fewer (42%) of the 26 who had worn the shoes regularly than of the 15 who had worn the shoes irregularly (87%, p less than 0.01). At follow-up, only 15% of the 41 patients were being treated for foot-lesions, compared with 78% of these 41 patients before cushioned shoes were provided. It is concluded that the availability of therapeutic shoes with cushioned insoles for diabetic patients at risk of foot lesions decreases the morbidity due to the diabetic foot syndrome.

Uniform elimination pattern for glibenclamide in healthy Caucasian males

It has been shown, that the elimination rate of intravenously administered tolbutamide shows considerable interindividual variation, due to strong genetic influence. These pharmacogenetic differences in the metabolic clearance rate of tolbutamide may result in drug failure in fast-eliminators, and it may cause an increased incidence of side effects in slow-eliminators. It is not known whether different "pharmacogenetics" exist for other sulfonylurea drugs. Therefore, we have injected glibenclamide (0.02 mg/kg body weight) intravenously in 52 male, normal weight, healthy volunteers. Serum glibenclamide levels were followed for up to 24 h. The terminal phase half-life of glibenclamide was 2.46 +/- 0.67 h (mean +/- SD), total drug clearance was 48.7 +/- 11.0 ml.min-1 and the slow disposition phase rate constant was 0.30 +/- 0.08 h-1. From the individual data of each subject frequency histograms were developed for these and other kinetic parameters and tested with a Kolmogoroff-Smirnoff-test for unimodal normal distribution. There was no significant (p greater than 0.05) deviation from the unimodal normal distribution for these parameters. In contrast to the pharmacogenetics of tolbutamide metabolism the present data indicate that glibenclamide follows an uniform elimination pattern in healthy caucasian males.

Long-term safety, efficacy and side-effects of continuous subcutaneous insulin infusion treatment for type 1 (insulin-dependent) diabetes mellitus: a one centre experience

A follow-up study of 116 Type 1 (insulin-dependent) diabetic patients on long-term continuous subcutaneous insulin infusion was conducted after 4.5 +/- 0.2 years. The average HbA1c-value of these patients decreased by 1% to 6.7 +/- 0.1% during this observation period. Typical side effects of continuous subcutaneous insulin infusion such as skin inflammation at the catheter insertion site occurred with similar frequency as has been reported previously by other authors. Diabetic ketoacidosis (0.14 per patient year) and disabling hypoglycaemia (0.1 per patient year, including 0.05 hypoglycaemic coma per patient-year) occurred at substantially lower rates than in other comparable studies with Type 1 diabetic patients at a similar degree of metabolic control. Subgroup evaluation suggested that a normal (less than 5.6%) HbA1c-value at follow-up was associated with increased incidence of disabling hypoglycaemia, whereas poor metabolic control (HbA1c greater than 7.5%) was associated with increased rates of skin complications and hospital treatment for ketoacidosis. Thus, under the policies of this diabetes centre, continuous subcutaneous insulin infusion has proved to be beneficial to a large proportion of experienced adult Type 1 diabetic patients, who voluntarily had opted for, and continued with, this particular mode of insulin treatment.