Immediate and long term effects of weight reduction in obese people with asthma: randomised controlled study

OBJECTIVE

To investigate the influence of weight reduction on obese patients with asthma.

DESIGN

Open study, two randomised parallel groups.

SETTING

Private outpatients centre, Helsinki, Finland.

PARTICIPANTS

Two groups of 19 obese patients with asthma (body mass index (kg/m(2)) 30 to 42) recruited through newspaper advertisements.

INTERVENTION

Supervised weight reduction programme including 8 week very low energy diet.

MAIN OUTCOME MEASURES

Body weight, morning peak expiratory flow (PEF), forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)); and also asthma symptoms, number of acute episodes, courses of oral steroids, health status (quality of life).

RESULTS

At the end of the weight reducing programme, the participants in the treatment group had lost a mean of 14.5% of their pretreatment weight, the controls 0.3%. The corresponding figures after one year were 11.3% and a weight gain of 2.2%. After the 8 week dieting period the difference in changes in percentage of predicted FEV(1) from baseline in the treatment and control groups was 7.2% (95% confidence interval 1.9% to 12.5%, P=0. 009). The corresponding difference in the changes in FVC was 8.6% (4. 8% to 12.5%, P<0.0001). After one year the differences in the changes in the two groups were still significant: 7.6% for FEV(1) (1. 5% to 13.8%, P=0.02) and 7.6% for FVC (3.5% to 11.8%, P=0.001). By the end of the weight reduction programme, reduction in dyspnoea was 13 mm (on a visual analogue scale 0 mm to 100 mm) in the treatment group and 1 mm in the control group (P=0.02). The reduction of rescue medication was 1.2 and 0.1 doses respectively (P=0.03). After one year the differences in the changes between the two groups were -12 for symptom scores (range -1 to -22, P=0.04) and -10 for total scores (-18 to -1, P=0.02). The median number of exacerbations in the treatment group was 1 (0-4) and in the controls 4 (0-7), P=0.001.

CONCLUSION

Weight reduction in obese patients with asthma improves lung function, symptoms, morbidity, and health status.

Maintenance programmes after weight reduction--how useful are they?

Maintenance programmes lasting one or two years or even longer are generally recommended to improve long-term outcome after weight reduction. They may not be practical for several reasons: it is not known whether they really improve long term outcome or only delay relapse; they may lessen patients' motivation to take full responsibility for their life-style changes; and they need extra resources. Some series on treatment of obesity and experience with successful maintainers suggest that satisfactory long-term outcome can also be achieved without long maintenance programmes. We believe that weight reduction programmes lasting 4-6 months can be developed to ensure better maintenance. The programmes should adopt a patient centred approach, support patients' full responsibility for life-style changes, and use principles and methods acceptable for most obese people.

Testing of human homologues of murine obesity genes as candidate regions in Finnish obese sib pairs

The human homologues of recently discovered murine obesity genes provide relevant candidates to study the genetic component of obesity in humans. We analysed the human counterparts to murine obesity genes ob, db, agouti, tub, melanocortin 4-receptor (MC4-R) and mitochondrial uncoupling proteins 2 and 3 (UCP2 and UCP3), as well as two other chromosomal regions reported to be linked to obesity-related phenotypes in restricted populations. We found no significant evidence for linkage to any analysed loci in our total study material of 105 affected sib pairs collected from the genetically homogenous population of Finland. However, several markers on 14 cM chromosomal region flanking the MC4-R gene showed sharing of alleles identical-by-descent (IBD) more frequently than expected. A selected subset of non-diabetic obese sib pairs strengthened the P values down to 0.003 in this particular region. The smallest P value (P = 0.001) was obtained with a marker D18S487 in a subgroup containing only sib pairs with one lean and one obese parent. We therefore screened seven obese subjects included in our sib pair material for sequence changes in their MC4-R gene, but no mutations of apparent causal relationship were found. In conclusion, we could not find evidence for significant contribution of the chromosomal loci corresponding to the murine single gene obesity genes for human morbid obesity, but additional studies are still needed to clarify whether DNA alterations within or adjacent to the MC4-R gene play some role.

A nurse-managed weight reduction programme for obstructive sleep apnoea syndrome

OBJECTIVES

This longitudinal, clinical intervention study was designed to investigate whether pulmonary departments can set up a cost-effective weight and lifestyle programme as primary treatment of obstructive sleep apnoea syndrome (OSAS).

SETTING

A weight reduction programme (1 year) in a pulmonary department for outpatients in Helsinki University Central Hospital.

SUBJECTS

A total of 24 (23 men) moderately obese (body mass index [BMI], 30-40 kg m(-2)) patients with newly diagnosed OSAS. Interventions. The first 6 weeks consisted of a very low-calorie diet (VLCD, 500 kcal day(-1)) and thereafter normal food low in calories. There were altogether 12 group meetings for behavioural management.

MAIN OUTCOME MEASURES

Daytime somnolence, BMI and oxygen desaturation index of 4% (ODI4) were measured prior to the programme, at the end of the VLCD phase and at 1 year.

RESULTS

The programme was easy to administer without any serious side-effects. At 1 year, patients had lost a mean of 33% of their overweight (mean weight at baseline 110 kg, after 99 kg) and their ODI4 indexes improved significantly (P < 0.005). There was no correlation between the amount of weight loss and improvement in ODI4 indexes. The cost per patient was about half the cost of treatment with nCPAP (nasal continuous positive airway pressure) for 1 year at our hospital.

CONCLUSIONS

A nurse-managed programme with VLCD and behavioural management is safe and effective on an outpatient basis. Weight loss should be encouraged in OSAS in patients with moderate overweight. The amount of weight loss needed for improvement of OSAS is unique to each individual.

Weight loss with very-low-calorie diet and cardiovascular risk factors in moderately obese women: one-year follow-up study including ambulatory blood pressure monitoring

OBJECTIVE

The beneficial effects of weight loss with a very-low-calorie diet (VLCD) on cardiovascular risk factors have been reported at the end of energy restriction. As the effects, especially on blood pressure, may not remain constant during weight maintenance, we studied the longer-term effects of weight loss on 24h ambulatory blood pressure (ABP), lipids, glucose and insulin.

DESIGN

Prospective study of a 17-week weight loss programme containing an eight-week VLCD period and follow-up visit at one-year.

SUBJECTS

Twenty-nine moderately obese, normotensive or mildly hypertensive women. The mean +/- s.d. body mass index (BMI) was 36.0 +/- 2.6 kg/m2 and mean age 40.3 +/- 8.3 y.

RESULTS

In the last week of the VLCD, the mean (s.d.) weight loss was 12.4 +/- 3.3 kg (P < 0.001), at the end of the programme 15.1 +/- 4.4 kg (P < 0.001 vs baseline), and at one-year follow-up 10.7 +/- 7.6 kg (P < 0.001 vs baseline). Mean 24 h ABP decreased 8.0/4.6 mmHg (P < 0.001 for both) on the last week of the VLCD, at the end of the programme, the systolic ABP decrease was 4.7 mmHg (P < 0.01 vs baseline) and diastolic 2.1 mmHg (not statistically significant (NS) vs baseline). At one-year follow-up, the mean systolic ABP decrease was 4.1 mmHg (P < 0.01 vs baseline) and mean diastolic 3.0 mmHg (P < 0.05 vs baseline). Sodium excretion decreased 55 mmol/24 h in the last VLCD week (P < 0.01) and returned to baseline after that. At the one-year follow-up, beneficial changes, compared with baseline, were observed in mean serum glucose (-0.28 mmol/l, P < 0.05), triglyceride (-0.35 mmol/l, P < 0.01) and HDL cholesterol (+0.16 mmol/l, P < 0.001).

CONCLUSIONS

This weight loss programme with a VLCD enabled obese subjects to lose weight and decrease cardiovascular risks. Despite some regain in weight during follow-up, the beneficial effects were overall maintained over the year. Sodium intake tended to increase during follow-up. Information on sodium restriction should be included in weight loss programmes.

A common pentanucleotide polymorphism of the 3'-untranslated part of the leptin receptor gene generates a putative stem-loop motif in the mRNA and is associated with serum insulin levels in obese individuals

OBJECTIVE

To find out whether genetic alterations of the leptin receptor gene underlie human forms of obesity.

DESIGN

Among 249 morbidly obese adults (body mass index, BMI > or = 40 kg/m2), we screened 30 patients with the highest serum leptin levels for alterations of their leptin receptor gene by single-strand conformation polymorphism (SSCP) technique.

SUBJECTS

249 severely obese subjects (present or past BMI > or = 40 kg/m2) and 138 lean controls (BMI < or = 25 kg/m2).

MEASUREMENTS

DNA analysis was carried out using SSCP technique, sequencing and polymerase chain reaction (PCR) followed by digestion with the restriction enzyme Rsal. Serum leptin, glucose, insulin and lipid concentrations were determined in obese subjects.

RESULTS

We were able to detect a pentanucleotide insertion (CTTTA) in the 3'-untranslated region of the leptin receptor gene. The presence of this pentanucleotide insert generates a putative stem-loop structure in the mRNA. Association studies were carried out on this variant. The frequency of the insertion allele did not differ between 249 obese (12.4%) and 138 lean (12.0%) subjects. There was no association of serum leptin, glucose or lipid levels with the pentanucleotide genotype in the obese individuals. However, when subjects without medication affecting insulin or glucose levels were considered, serum insulin levels were found to be lower in the heterozygous carriers of the insertion allele (15.1 +/- 9.2 mU/l) than in the subjects homozygous for the deletion allele (21.8 +/- 13.7 mU/l, P = 0.0035).

CONCLUSIONS

We were able to confirm the presence of a frequent insertion/deletion polymorphism close to the 3'-end of the leptin receptor gene. We also showed that serum insulin levels in morbidly obese subjects are associated with 3'-UTR variant genotype.

Three splicing defects, an insertion, and two missense mutations responsible for acute intermittent porphyria

Three splicing defects (IVS1+3G-->T, 86A-->T, IVS13-2A-->G), an insertion (416insCA), and two missense mutations (664G-->A and 833T-->G) in the porphobilinogen deaminase (PBGD) gene were identified in six unrelated Finnish patients with acute intermittent porphyria (AIP). The IVS1+3G-->T substitution resulted in activation of a cryptic splice site in intron 1 and retention of a 67-bp fragment in the mutant transcript. The 86A-->T mutation at the end of exon 3 was predicted to cause an amino acid substitution (E29L). However, sequencing of the cDNA sample of the proband revealed exon 3 skipping from the mutant transcript. The IVS13-2A-->G substitution caused retention of intron 13 in the mutant transcript. In exon 8, 416insCA resulted in a frameshift. All three splicing defects and the CA insertion resulted in a truncated protein and thus, probably the loss of PBGD activity. The two novel missense mutations, 664G-->A in exon 12 and 833T-->C in exon 14 caused a single amino acid substitution (V222M and L278P). So far 25 different mutations have been characterized from 37 (93%) of a total of 40 unrelated Finnish AIP families, confirming the genetic heterogeneity of the disease even in a previously isolated area of Finland.

Acute porphyria: treatment with heme

The characterization of porphyrias as disorders of heme biosynthesis leading to hepatic heme deficiency and raised formation and secretion of heme precursors laid the basis for heme treatment. Although mild attacks sometimes respond to glucose administration, severe attacks or symptoms that are likely to progress should be treated with heme. The heme compounds used in treatment are hematin and heme arginate. In our opinion, heme arginate is preferable to hematin in the treatment of acute porphyrias because of its better stability, fewer side effects, and better documentation of its benefits.

Steady-state transcript levels of the porphobilinogen deaminase gene in patients with acute intermittent porphyria

PCR-based solid-phase minisequencing method was used to analyze the steady-state mRNA levels of the porphobilinogen deaminase gene in eight patients with acute intermittent porphyria. The patients had the earlier characterized mutations 517C --> T (R173W), 518G --> A (R173Q), 673C --> G (R225G), 673C --> T (R225X), 713T --> G (L278P), and 1073delA (frame shift). All mutations, except the missense mutation 517C --> T in exon 10, affected the steady-state transcript levels of the mutant allele. The mutant mRNA levels in lymphocytes varied from 5% to 95% of the corresponding wild-type allele levels. In contrast to the CRIM-negative mutation 517C --> T, the CRIM-positive mutation in the same codon 518G --> A resulted in reduction of the steady-state transcript level of the mutant allele to 65% of that of the normal allele. The two mutations, 673C --> G or T, affecting the same nucleotide in exon 12 also differed considerably in their effect on mRNA levels: The transcript level of the allele with a missense mutation was decreased to 80% of that of the normal allele, whereas a nonsense mutation at the same position resulted in a dramatic decrease (fivefold) in the levels of the mutant transcript. Our data showed large variations between the levels of mutant transcript in AIP patients and these variations did not correlate either to CRIM class, to the location of the disease causing mutation in the PBGD gene, or to the clinical phenotype of AIP.

Use of very low-calorie diet in preoperative weight loss: efficacy and safety

We report the efficacy of a very low-calorie diet (VLCD)-based weight reduction program in patients with morbid obesity whose elective surgery had been postponed because of being overweight. The safety of weight loss on the immune system will also be evaluated. Thirty patients (mean age, 50 years; weight, 125 kg; BMI, 44 kg/m2) were treated. The program consisted of a 7-week to 24-week VLCD period, supported by individual sessions with a therapist, and of a refeeding period of 1 month before surgery. Two patients discontinued, and the mean weight loss of the remaining 28 patients was 19.6 kg (15% of initial weight). In 23 patients, weight loss was 10% or more of the initial weight. After weight loss, 15 patients underwent surgery, 4 patients did not need an operation, and the remaining 9 patients were not operated on for various reasons. The numbers of circulating leukocytes, neutrophils, basophils, monocytes, CD3+, CD4+, CD8+, and natural killer cells did not change significantly by the ninth week on VLCD or by the end of the program. However, there was a significant (p < 0.05) decrease in the immunoglobulinM serum concentration during the program. In conclusion, a VLCD program is suitable for preoperative weight reduction in morbid obesity and seems not to compromise the immune system.

Comparison of behavior therapy with and without very-low-energy diet in the treatment of morbid obesity. A 5-year outcome

BACKGROUND

Very-low-energy diets (VLEDs) together with behavior therapy (BT) are widely used in the treatment of morbid obesity, but there is no evidence of their long-term effectiveness as compared with behavior therapy alone.

METHODS

Fifty-nine morbidly obese patients (25 men and 34 women; mean weight, 132.8 +/- 20.7 kg; mean age, 43.1 +/- 9.2 years) were treated with combined therapy of VLED and BT or BT alone. No maintenance program was used. Eighty-seven percent of eligible patients were contacted 4.8 to 6.2 years after the program.

RESULTS

During treatment, 56% of patients dropped out of the VLED + BT group and 28% from the BT group (P = .03). High scores on the Symptom Checklist-90R before treatment predicted dropout from the VLED+BT group, but not from BT. At the end of therapy, mean weight change was -22.9 kg in the VLED+BT group and -8.9 kg in the BT group (P < .001). The overall weight change from pretreatment to the 5-year follow-up was greater in the VLED+BT group than in the BT group (-16.9 kg vs -4.9 kg, respectively; P = .03). Men succeeded better in the VLED+BT group than in BT. Among the dropouts, the mean weight change from baseline was +5.2 kg in the VLED+BT group and +13.0 kg in the BT group.

CONCLUSIONS

Our data suggest that in the treatment of morbid obesity, VLED combined with BT may produce a better 5-year maintenance than BT alone, especially among men. A satisfactory weight loss can be achieved without a maintenance program.

Novel polymorphism of the human ob gene promoter in lean and morbidly obese subjects

OBJECTIVE

Leptin, the circulating product of the human ob gene, may play role in control of appetite and metabolic rate. We screened the proximal promoter area of the ob gene for mutations and common polymorphisms in order to find out whether genetic variation in the regulatory area of this gene plays a role in human obesity.

DESIGN

The technique of single-strand-conformation polymorphism (SSCP) was applied to screen for the promoter area of the ob gene for genetic alterations in morbidly obese patients.

SUBJECTS

A total of 249 morbidity obese (present or past body mass index [BMI] > or = 40 kg/m2) and 141 lean (BMI < or = 25 kg/m2) subjects.

MEASUREMENTS

DNA analysis was carried out using a single-strand conformation polymorphism (SSCP) technique and PCR followed by digestion with the restriction enzyme BssHll. Leptin was determined by radioimmunoassay in obese subjects. Serum lipids, glucose and insulin concentrations in the obese subjects were also determined.

RESULTS

A new polymorphism C(-188)A was identified in the promoter region of the ob gene. This polymorphism was detected with allelic frequencies of 0.06 in morbidly obese subjects and 0.09 in lean controls (P = 0.28). Initial studies failed to show an association of this polymorphism with serum leptin, response to treatment for obesity, history and extent of weight gain, or serum insulin, glucose of lipid concentrations.

CONCLUSIONS

We have identified a common polymorphism in the promoter area of the human ob gene which appears to be very useful for genetic association and linkage studies. Further studies are needed to elucidate its potential role in the regulation of the human ob gene and in human metabolic disorders.

Markers for the gene ob and serum leptin levels in human morbid obesity

Leptin, the product of the ob gene, reduces body fat in genetically obese animals and circulates in elevated concentrations in the blood of obese patients. Polymorphic markers situated in the proximity of the human ob gene have recently been suggested to be linked to morbid obesity. We have studied the possible association between the microsatellite markers near the ob gene and morbid obesity in 252 morbidly obese patients with a mean body mass index (BMI) of 43 +/- 7 kg/m2, and 151 lean controls with a mean BMI of 22 +/- 2 kg/m2, and searched for linkage of these gene markers to obesity in 76 affected sib-pairs (BMI > or = 32). No significant association was observed between any of the eight microsatellite markers and morbid obesity, and affected-sib-pair analysis failed to show linkage of three selected ob gene markers to obesity in the sibships. There was a strong positive correlation between serum leptin levels and BMI in morbidly obese patients; a carrier status for either of the two most prevalent alleles of the microsatellite marker D7S530 in the vicinity of the ob gene was associated with serum leptin levels in the obese subjects. Two of the markers (D7S2519, D7S649) showed a significant relation to the weight-losing response to a 16-week very-low-calorie dietary intervention. We have thus been able to confirm a tight relationship between serum leptin and body mass but have found no evidence for genetic linkage of the ob gene markers to morbid obesity in a population considered to represent a genetic isolate and to be an ideal model for studies of complex disorders.

Polymorphism of the beta 3-adrenergic receptor gene in morbid obesity

OBJECTIVE

The Trp64-->Arg allele of the beta 3-adrenergic receptor gene was recently proposed to be associated with an earlier onset of non-insulin-dependent diabetes mellitus (NIDDM), features of insulin resistance and a tendency to gain weight. We investigated whether the Arg64 allele predisposes to severe obesity.

DESIGN AND SUBJECTS

A genetic association study of 254 subjects with morbid obesity [body-mass index (BMI) > or = 40; mean 42.8 +/- 7.0] and 151 lean healthy control subjects [BMI < or = 25; mean BMI 22.3 +/- 1.9].

MEASUREMENTS

beta 3-adrenergic receptor genotyping was carried out with a solid-phase minisequencing technique. Serum lipids, glucose and insulin levels in the obese subjects were also determined.

RESULTS

The frequency of the Arg64 did not significantly differ in the morbidly obese patients (9.1%) and lean controls (8.9%), nor was there any statistically significant association between the mean BMI values and the beta 3-adrenergic receptor genotype. However, obese subjects carrying the Arg64 allele developed obesity more often before the age of 15 y than those without it (P < 0.05, adjusted for multiple comparisons). The frequency of the Arg64 allele was similar in nondiabetic and diabetic patients; the mean age at the onset of NIDDM did not differ according to the beta 3-adrenergic receptor genotype. There was no significant association between the receptor genotype and the level of the serum cholesterol, HDL-cholesterol, triglyceride, glucose or insulin, nor was this polymorphism associated with the behavioural or psychopathological characteristics of the morbidly obese subjects. Response to a 16 w treatment program including a very-low calorie diet (VLCD) regimen, dietary and exercise counseling, as well as behavioural modifications, did not differ according to the genotype.

CONCLUSION

Our data do not support a significant role for the codon 64 polymorphism of the beta 3-adrenergic receptor as a genetic marker of morbid obesity. Although there was an association between the Arg64 allele and an earlier onset of obesity in individuals subsequently developing morbid obesity, this allele was not associated with the actual BMI gained or response to weight-loss therapy on a hypocaloric diet.

Improved gas exchange during exercise after weight loss in morbid obesity

The aim of this study was to determine the effect of weight loss induced by 6 weeks very-low-calorie-diet (VLCD) and behavioural intervention on pulmonary gas exchange during exercise in non-smoking morbid obese (BMI>40 kg/m2) otherwise healthy patients. Seven obese patients underwent a maximal bicycle ergometer test with continuous analysis of expired air and arterial blood sampling before and after a mean weight loss of 18% (25.7 kg, range: 10-50 kg). Body mass index (BMI) decreased with weight loss from 46.6 (6.3) kg/m2 to 38.0 (4.7) kg/m2 (P<0.01). Oxygen consumption (VO2) at low and submaximal exercise levels decreased after weight reduction, but the change was not statistically significant. The peak oxygen consumption related to body weight (VO2/kg) increased 22% from the initial 16.2 (3.6) ml/min/kg to 19.8 (3.1) ml/min/kg (P<0.05). Decrease in VCO2 was significant at submaximal exercise level. Ventilatory equivalent for CO2 increased significantly after weight reduction (P<0.05). Standing up and light exercise resulted in a significant increase in the mean arterial oxygen tension (PaO2) (P<0.05) and a significant decrease in the mean alveolar-arterial difference P(A-a)O2 (P<0.05) when compared to supine values. The mean increase in PaO2 with weight loss was not significant. The peak P(A-a)O2 decreased significantly after weight reduction. In conclusion, weight reduction induced by VLCD and behavioural intervention without exercise therapy can improve gas exchange during exercise in morbid obesity. Increased wasted ventilation, and a tendency to alveolar hyperventilation, after weight loss may reflect a delay in the adaptation of regulation of breathing to rapid weight loss.

Two year maintenance of weight loss after a VLCD and behavioural therapy for obesity: correlation to the scores of questionnaires measuring eating behaviour

OBJECTIVE

To investigate changes in weight, Three Factor Eating Questionnaire and Binge eating scores during a two-year period from the start of a VLCD (Nutrilett) and behavioural modification therapy for obesity.

DESIGN

Prospective study of a 17-weeks weight loss programme with one- and two-year follow-up visits.

SUBJECTS

62 healthy, overweight subjects without previous eating disorders. The mean (+/- SD) age 41 +/- 8 years and BMI 36.4 +/- 2.6 kg/m2.

MAIN OUTCOME MEASURES

Weight loss, Binge eating scale, Bulimic Investigatory Test and Three Factor Eating Questionnaire before and after therapy and at 1 and 2 year control visits.

RESULTS

The mean weight loss (+/- SD) at the end of the treatment was 14.9 +/- 4.6 kg (n = 59) and at the two-year control 5.8 +/- 7.6 kg (n = 57). After two years 20 (32%) patients had a weight loss of more than 10% (good result), 24 patients a weight loss of 0-10% of their initial weight (partial result) and 13 patients weighed more than before therapy (poor result). The mean binge eating, disinhibition and hunger scores decreased in all patients by the end of the therapy. At the end of two years these improvements in the scores were maintained in patients with a good result but the scores returned to the pretreatment levels in the patients with partial or poor result. The mean restraint scores increased in all patients after treatment and were maintained in those with a good or partial result.

CONCLUSIONS

VLCD combined with behaviour modification is a useful mode of therapy for obesity with low drop-out rate and majority (71%) of patients below pretreatment weight at the two-year control. One third of the patients succeeded to maintain positive changes in the scores measuring eating behaviour which was associated with sustained weight loss.

Four novel mutations in the ferrochelatase gene among erythropoietic protoporphyria patients

A novel mutation was identified by direct sequencing of genomic polymerase chain reaction products in each of four Finnish erythropoietic protoporphyria families. All four mutations, including two deletions (751delGAGAA and the first de novo mutation, 1122delT) and two point mutations (286C-->T and 343C-->T), resulted in a dramatically decreased steady-state level of the allelic transcript, since none of the mutations could be demonstrated by direct sequencing of the amplified cDNAs synthesized from total RNA extracted from patients' lymphoblast cell lines. Because the assays of the ferrochelatase activity and erythrocyte protoporphyrin identify asymptomatic patients poorly, the DNA-based demonstration of a mutation is the only reliable way to screen individuals for the disease-associated mutation.

Effect of weight loss and body position on pulmonary function and gas exchange abnormalities in morbid obesity

OBJECTIVE

To determine, whether behavioral management of obesity including very-low-calorie-diet would produce weight loss enough to improve pulmonary mechanics and gas exchange in morbid obesity.

DESIGN

Pulmonary function and arterial oxygenation were studied before and after weight loss in 11 patients attending a group therapy with the program of VLCD for 6 weeks and 16 weeks' behavioral intervention.

MEASUREMENTS

Spirometry, diffusing capacity, body plethysmograph, closing volume and arterial blood gas analyses.

RESULTS

The mean initial BMI was 45.4 kg/m2 (range 39.8-58.7 kg/m2) and decreased to 39.4 kg/m2 (range 31-49.8 kg/m2) (P < 0.01). Expiratory reserve volume (ERV) and functional residual capacity (FRC) improved significantly with weight loss. Closing capacity (CC) exceeded FRC in 10 cases of 11 at the initial stage, but after weight loss only in three patients. The mean arterial oxygen tension with the patients in supine position did not change after weight loss, but standing up improved PaO2 significantly before and after weight loss.

CONCLUSION

The dietary treatment of morbid obesity was sufficient to induce improvement in lung volumes, but not enough to improve arterial oxygenation, although ventilatory mechanics was improved significantly and the tendency to early small airway closure was decreased. Hypoxemia was significantly relieved by standing up both before and after weight loss.

Acute intermittent porphyria in Finland: 19 mutations in the porphobilinogen deaminase gene

The sensitivity of single-strand conformation polymorphism (SSCP) analysis for the detection of mutations in the porphobilinogen deaminase (PBGD) gene among Finnish patients with acute intermittent porphyria (AIP) was studied. 13 novel mutations including one de novo event, and six previously characterized mutations were identified among AIP patients. The 19 mutations reported here for 28 families cover 72% of all the AIP families in the Finnish population of five million. When compared to direct sequencing, SSCP-analysis detected 17 (89%) of the 19 mutations when a combination of various electrophoretic conditions were used. The most informative electrophoretic condition was a gel run without glycerol in the coldroom (11/18 mutations). 86% of mutations were identified from amplified fragments greater than 300 bp and detection was dependent on both the amount of glycerol in the gel and the running temperature, but seemed to be independent of the size of the analyzed fragment or the type of mutation. The diagnostic efficiency of biochemical assays versus mutation screening in the PBGD gene was studied in three large AIP families, each representing different CRIM subtypes of AIP. The results demonstrated that using assays of erythrocyte PBGD activity, the majority (82%) of family members (n = 51) were diagnosed correctly. Of a total of 81 family members, 30 of whom had deficiency of PBGD confined to non-erythroid tissues, diagnosis at the asymptomatic stage of disease in 11 individuals (14%) required the application of mutation screening.

Effects of a cognitive-behavioural weight loss programme on overweight obstructive sleep apnoea patients

Thirty-two obese patients (Body Mass Index (BMI) = 38.5 +/- 3.7) with obstructive sleep apnoea (the average number of oxygen desaturations per hour of sleep exceeding 4% from the baseline (ODI4) = 38.64 +/- 23.9) underwent a one-year cognitive-behavioural weight reduction programme with a one year follow-up period. The criteria for successful treatment were (i) a decrease in ODI4 to less than 10 and (ii) a decrease in ODI4 that was greater than 50%. Fourteen (44%) patients were considered to be treated successfully at six months. When the patients were grouped according to weight loss 23 patients had lost more than 5 kg; 12 (52%) of them belonged to the group treated successfully. At 24 months, however, only three (9%) patients could be regarded as treated successfully and six patients had been transferred to other treatment modes (Nasal Continuous Positive Airway Pressure (nCPAP) and uvulopalatopharyngoplasty (UPPP)). The changes in weight correlated with the changes in ODI4 (r = 0.47 and 0.63 at the 6-month and the 24-month evaluation, respectively).

Long-term Results of Gastroplasty for Morbid Obesity: Binge-Eating as a Predictor of Poor Outcome

We investigated the long-term results after vertical banded gastroplasty (VBG) for morbid obesity and evaluated some predictors of poor outcome. Twenty-seven morbidly obese patients (mean BMI 50 kg/m(2)) who underwent VBG a mean of 5.4 years earlier were studied. The mean weight loss was 31 kg or 40.5% of excess weight. Ten patients (37%) were within 50% of their ideal weight. The patients were classified as bingers (n = 10) and non-bingers (n = 17) according to the modified Binge Eating Scale. One-year postoperative weight losses were 55% and 57% respectively of excess weight, but at the time of the study weight losses were 24% and 50% of excess weight (p = 0.04) in the bingers and non-bingers, respectively. The mean weight regain was 23 kg in the bingers vs 8 kg in the non-bingers, p = 0.01. Two bingers had excellent weight loss results, but otherwise an unsuccessful outcome. Weight reduction did not correlate with age, sex or age of onset of obesity. These results show that binge-eating strongly predicts poor weight loss maintenance after gastroplasty in the long-term, though initial weight reduction is good. We suggest that binge-eating should be evaluated before gastroplasty and taken into consideration in the design of treatment.

Effects of heme arginate on cytochrome P450-mediated metabolism of drugs in patients with variegate porphyria and in healthy men

We investigated the effects of heme on metabolism of coumarin, debrisoquin, caffeine, and lidocaine in seven female patients with variegate porphyria and in 10 healthy men. During baseline conditions metabolism of the drugs was identical in the two groups. Compared with the results without heme, a single infusion of heme arginate (3 mg/kg heme) significantly decreased the debrisoquin/4-hydroxy-debrisoquin metabolic ratio in subjects with porphyria (p = 0.016) and in the control subjects (p = 0.016) and increased formation of monoethylglycinexylidide from lidocaine (p = 0.016 and p = 0.004, respectively). Metabolism of coumarin and caffeine was not affected by heme. Our results show that, in patients with porphyria and in healthy subjects, exogenous heme is able to accelerate the reactions mediated by the cytochrome isozymes CYP2D6 (debrisoquin) and CYP3A4 (lidocaine) but not reactions mediated by CYP1A2 (caffeine) and CYP2A6 (coumarin). This suggests that influence of heme on drug metabolism is P450 isozyme-specific.