A review of maternal behaviour in dogs and potential areas for further research

Here we review information on maternal behaviour in dogs, defined as a combination of all the acts of the mother towards her offspring, which begins before parturition and continues until weaning. In dogs, maternal care is measured using the most commonly observed behaviours, such as the time spent in contact, licking/grooming and nursing of the puppies. Since newborn puppies have a very limited capacity for movement, maternal interaction is essential to their survival, nourishment and protection. It is also an important element of the bonding process between puppies and the bitch and is thought to play a role in the social development of the puppies. Nevertheless, some questions still need to be clarified, such as the best way to quantify factors that may interfere with maternal behaviour. In recent studies, maternal care, or maternal style, was measured using a scoring system and found to be influenced by factors such as litter size, breed and parity, or even human interaction. However, the impact of the emotional state of the bitch and the quality of maternal behaviour on puppy survival and development remain unclear. The long-lasting effects of mother-puppy interactions on puppy behaviour during their adult life are still poorly understood, despite their importance for breeders who wish to prevent future problem behaviours.

Triplex doppler ultrasonography to describe the uterine arteries during diestrus and progesterone profile in pregnant and non-pregnant bitches of different sizes

Hemodynamics of uterine vascularization is modified throughout pregnancy to meet the increasing demand of the growing fetuses and triplex doppler ultrasonography is widely used in human medicine to study the uterine arteries and assess the fetal and placental conditions. The aim of our study was to confirm this observation in the bitch, to evaluate differences between bitches of different sizes and to study abnormal pregnancies. Forty-four bitches were monitored during the estrous period to determine ovulation and every 10 days from ovulation to 50 days post-ovulation: the resistivity (RI) and pulsatility (PI) indexes of the right uterine artery were measured as well as usual assessment of fetal development and follow up of the luteal function. Thirty-three out of forty-four bitches were pregnant, including 6 abnormal pregnancies (resorption of more than 10% of the embryos). We also divided them in four weight categories: 8 were small (<10 kg), 13 medium (10-25 kg), 13 large (>25-40 kg) and 10 were giant breeds (>40 kg). We observed that RI and PI decreased over time and were significantly lower for pregnant bitches compared to non-pregnant ones from 30 days post-ovulation. In contrast, RI and PI did not significantly vary with the size of the bitches and we could not determine a significant impact of abnormal pregnancies either. In conclusion, we found no significant difference related to the size of bitches in the RI and PI. The only significant difference between pregnant and non-pregnant bitches was observed from 30 days post-ovulation.

A retrospective study of canine prostatic diseases from 2002 to 2009 at the Alfort Veterinary College in France

A retrospective study was used to investigate the incidence of prostatic diseases in a large population of dogs at Alfort Veterinary Hospital and to clarify epidemiologic features, which might be of a great help to veterinarians in managing and discriminating prostatic disorders. During the investigation period, a total of 72,300 male dogs (coming mainly from the Ile-de-France region) were registered in the Alfort Veterinary College database, and 481 of them (0.7%) were found to have prostatic disorder. The diagnosis was carried out on the basis of clinical signs and ultrasound findings. Among dogs experiencing a prostatic disorder, most frequently recorded diseases were benign prostatic hyperplasia (45.9%) and prostatitis (38.5%), followed by abscesses (7.7%), cysts (5.0%), neoplasia (2.6%), and squamous metaplasia (0.2%). Our study revealed an incidence of 0.3% of prostatic disorders observed in intact male dogs, except in the case of prostatic neoplasia. The mean age of the dogs experiencing prostatic disorders was 8.6 ± 3.2 years. This was significantly different (P < 0.001). Large dogs were significantly more affected by prostatic disorders (P < 0.05), except for prostatic neoplasia. A breed predisposition was suspected in German Shepherd (odds ratio [OR] = 2.1; 95% confidence interval [CI]: 1.5-2.9), Rottweiler (OR = 1.8; 95% CI: 1.2-2.7), American Staffordshire Terrier (OR = 3.8; 95% CI: 2.5-5.8), Berger de Beauce (OR = 3.7; 95% CI: 2.2-6.1), and Bernese Mountain Dog (OR = 2.5; 95% CI: 1.3-4.7).

Seminal fluid promotes in vitro sperm-oviduct binding in the domestic cat (Felis catus)

From many endangered or threatened species which are expected to profit from assisted reproduction techniques, mainly epididymal sperm of dead or freshly castrated males are available. These sperm had contact to epididymal secretion products but not to seminal fluid components. Notably, products of accessory sex glands have been shown in domestic animals to condition sperm for fertilization, in particular by mediating sperm-oviduct interaction. We report for the first time that motile epididymal sperm from domestic cats are able to bind to fresh oviduct epithelial cell explants from preovulatory females (median [min, max] of 10 [8, 16] and 10 [8, 17] sperm per 0.01 mm(2) explant surface from both isthmic and ampullar regions, respectively). More sperm attach to the explants when epididymal sperm were preincubated for 30 minutes with seminal fluid separated from electroejaculates of mature tomcats (median [min, max] of 17 [13, 25] and 16 [12, 21] sperm per 0.01 mm(2) explant surface from isthmus and ampulla, respectively). The proportion of bound sperm increased from a median of 54% to 62% by seminal fluid treatment. Sperm-oviduct binding could be facilitated by the decelerated sperm motion which was observed in seminal fluid-treated samples or supported by seminal fluid proteins newly attached to the sperm surface. Seminal fluid had no effect on the proportion of sperm with active mitochondria. Extent and pattern of sperm interaction in vitro were independent of explant origin from isthmus or ampulla. Sperm were attached to both cilia and microvilli of the main epithelial cell types present in all explants. In contrast to published sperm-binding studies with porcine and bovine oviduct explants where predominantly the anterior head region of sperm was attached to ciliated cells, the tails of some cat sperm were firmly stuck to the oviduct cell surfaces, whereas the heads were wobbling. Whether this response is a preliminary step toward phagocytosis or a precondition to capacitation and fertilization remains to be determined. In conclusion, treatment of epididymal sperm with seminal fluid or particular protein components should be considered in future investigations for its potential to improve the outcome of artificial insemination in felids.

Subclinical leishmaniasis associated with infertility and chronic prostatitis in a dog

A stud dog was presented for acquired infertility. Haematospermia and teratozoospermia were found on two ejaculates 2 weeks apart. A presumptive diagnosis of prostatitis was made follo-wing ultrasound examination. An ultrasound-guided needle core biopsy was performed under general anaesthesia, revealing a mild chronic macrophagic and plasma cell prostatitis with intracytoplasmic amastigotes consistent with Leishmania spp. infection. Presence of Leishmania infantum, Leishmania donovani or Leishmania chagasi was confirmed by polymerase chain reaction in seminal plasma. Serology and serum protein electrophoresis confirmed the diagnosis of a subclinical active systemic leishmaniasis. A meglumine antimoniate and allopurinol treatment was given which clearly improved within 3 months both general condition and the quality of sperm. To the authors' knowledge, this is the first reported case of a prostatitis secondary to a Leishmania spp. infection. Subclinical systemic leishmaniasis should be considered in the differential diagnosis of infertility in dogs suffering from semen alterations.

Induction of fertile oestrus in the bitch using Deslorelin, a GnRH agonist

Oestrus induction in various canine breeds was attempted in 32 bitches. A group of 8 bitches were treated 80-160 d following their previous oestrus (G1) whereas a second group of 24 bitches (G2) were implanted 200-590 d following their previous oestrus. The treatment for each bitch consisted in one Deslorelin implant (Suprelorin® 4,7 mg, Virbac, France), inserted subcutaneously in the post-umbilical region. Ovulation, pregnancy rate and litter size were recorded. All bitches came in heat 4.3 ± 1.4 d after implantation (2-7 d). Ovulation was reported in 62.5% in G1 and 87.5% in G2. One bitch refused mating and since no AI was performed, she was not considered for further analysis. Pregnancy was obtained in 25% in G1 versus 78.3% in G2. Mean litter size was 6.7 ± 3.5 puppies (1-14). Luteal failure was suspected in 3 bitches, two that remained non-pregnant and one which aborted 58 d post-ovulation since the owner refused progesterone supplementation. Deslorelin implants can therefore be considered as a valuable alternative to induce fertile oestrus in bitches in anoestrus. Follow-up of the luteal phase is recommended, since some bitches might encounter luteal failure.

Thyroid function and infertility in the dog: a survey in five breeds

In our study, a clinical and reproductive examination was undertaken in 204 dogs of five different breeds. Thyroxine and thyroid-stimulating hormone plasma concentrations were assayed in order to assess the real incidence of hypothyroidism associated with reproductive disease. Among these animals, only two breeds were affected by hypothyroidism (4.5% of the Dogue de Bordeaux and 2.4% of the Leonbergers). Moreover, these animals did not suffer from any reproductive disease. Our study showed also that 70% of the male Dogue de Bordeaux were hypothyroxinemic compared with Great Danes, English Mastiff and Leonbergers whose male population was 100% normothyroidic. We found the same tendency in bitches. In our data, there was no difference in thyroxin plasma concentrations between normo- and hypofertile dogs, but our results were not statistically significant.

Effects of 1-year treatment with metformin on metabolic and cardiovascular risk factors in non-diabetic upper-body obese subjects with mild glucose anomalies: a post-hoc analysis of the BIGPRO1 trial

AIM

Metformin has recently been considered as a possible pharmacological complement to lifestyle measures for preventing type 2 diabetes in high-risk subjects. However, little is known of its effects on metabolic and cardiovascular risk factors in non-diabetic subjects.

METHODS

The BIGPRO1 trial was a 1-year multicentre, randomized, double-blind, controlled clinical trial of metformin versus placebo, carried out in the early 1990s, in 457 upper-body obese non-diabetic subjects with no cardiovascular diseases or contraindications to metformin. We compared the changes (1-year minus baseline) in cardiometabolic risk factors between treatment groups in two subsets of trial subjects: those with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) (n=101); and those who fulfilled the inclusion criteria of the Diabetes Prevention Program (DPP) (n=51). Comparisons were adjusted for age and gender.

RESULTS

In the IFG/IGT subset, significant differences in 1-year changes were observed for systolic blood pressure, which decreased markedly more in the metformin group than in the placebo group (P<0.003), and for fasting plasma glucose, and total and LDL cholesterol, which decreased slightly in the metformin group, but increased in the placebo group (P<0.04). Similar results were observed in the subset with DPP criteria. Also, there were no significant differences in 1-year changes for weight, waist-to-hip ratio, 2-h post-load blood glucose, fasting and 2-h post-load insulin, HDL cholesterol, triglycerides and fibrinolytic markers between the two treatment groups.

CONCLUSION

In subjects at high risk of developing diabetes, the use of metformin showed beneficial and no untoward effects on cardiometabolic risk factors.

Evaluation of a structured educational programme for type 2 diabetes patients seen in private practice

AIM

Structured education is necessary in the management of a chronic disease such as diabetes and should be readily offered to patients in different settings. Our aim was to demonstrate the feasibility and advantages of a group education programme for type 2 diabetic patients in a private setting in France.

METHODS

A programme of group education for patients with type 2 diabetes was initiated by a multidisciplinary group of volunteer healthcare providers, including general practitioners, specialists in diabetology and non-medical members. All volunteers received one day of training, and physicians were instructed to organize several sessions of group education for the type 2 diabetic patients who regularly attended their practice. The first 427 patients entering the programme were included in the study, and asked to fill in a questionnaire to assess their knowledge, beliefs and behaviours with regard to diabetes. Their physician filled in a medical form. Six months later, the same questionnaire and form were sent for follow-up information.

RESULTS

At six months versus baseline, patients exhibited small, but consistent, improvements: (i) fasting glucose 142+/-42 mg/dL (P<0.04) vs 146+/-44 mg/dL (P<0.04); (ii) HbA(1c) 7.41+/-1.26% vs 7.57+/-1.33% (P<0.01); and (iii) all of the main parameters of diabetes self-management recorded in the study. The percentage of patients who inspected their feet at least once a week increased from 67 to 77% (P<0.001). Patients improved their knowledge of the disease and developed a more positive attitude towards their diabetes.

CONCLUSION

Our study demonstrates that it is possible to organize educational sessions for diabetic patients in a private-practice setting. At six months, patients receiving these sessions showed benefits in terms of blood glucose control and other important markers of self-management of their disease.

In vivo meiotic resumption, fertilization and early embryonic development in the bitch

Early development in canine species follows a very specific pattern. Oocytes are ovulated at the germinal vesicle stage and meiotic resumption occurs in the oviduct. However, because of difficulties in the accurate determination of ovulation time and in the observation of oocyte nuclear stage by light microscopy, these early events have not been fully described. Moreover, the oocyte stage at which sperm penetration occurs is still uncertain since fertilization of immature oocytes has been reported in vivo and in vitro. The aim of this study was to establish the exact timing of in vivo meiotic resumption, fertilization and early embryo development in the bitch with reference to ovulation. Ovulation was first determined by ultrasonography, artificial inseminations were performed daily and oocytes/embryos were collected between 17 and 138 h after ovulation. After fixation and DNA/tubulin staining, the nuclear stage was observed by confocal microscopy. Of the 195 oocytes/embryos collected from 50 bitches, the germinal vesicle stage was the only one present until 44 h post-ovulation, and the first metaphase II stage was observed for the first time at 54 h. Sperm penetration of immature oocytes appeared to be exceptional (three out of 112 immature oocytes). In most cases, fertilization occurred from 90 h post-ovulation in metaphase II oocytes. Embryonic development was observed up to the eight-cell stage. No significant influence of bitch breed and age on ovulation rate, maturation and developmental kinetics was observed. However, some heterogeneity in the maturation/development process was observed within the cohort of oocytes/embryos collected from one bitch. In conclusion, the most peculiar aspect of the canine species remains oocyte meiotic maturation whereas fertilization follows the same pattern as in other mammals.

Factors associated with upper respiratory tract disease caused by feline herpesvirus, feline calicivirus, Chlamydophila felis and Bordetella bronchiseptica in cats: experience from 218 European catteries

A full history of the management practices and the prevalence of upper respiratory tract disease (URTD) at 218 rescue shelters, breeding establishments and private households with five or more cats was recorded. Oropharyngeal and conjunctival swabs and blood samples were taken from 1748 cats. The prevalences of feline herpesvirus (FHV), feline calicivirus (FCV), Chlamydophila felis and Bordetella bronchiseptica were determined by PCR on swab samples. An ELISA was applied to determine the prevalence of antibodies to B. bronchiseptica. The rates of detection by PCR of each pathogen in the cats in catteries with and without ongoing URTD were, respectively, FHV 16 per cent and 8 per cent; FCV 47 per cent and 29 per cent; C. felis 10 per cent and 3 per cent; and B. bronchiseptica 5 per cent and 1.3 per cent; the seroprevalences of B. bronchiseptica were 61 per cent and 41 per cent, respectively. There was evidence that FHV, FCV and B. bronchiseptica played a role in URTD. The risk factors associated with the disease were less than excellent hygiene, contact with dogs with URTD, and larger numbers of cats in the cattery or household.

[Structure and function of the arteries of very elderly people. The PROTEGER Study (Cardiovascular Prognosis and Therapeutic Optimization in Geriatrics)]

The purpose of PROTEGER, a multicenter prospective observational study, was to determine the contribution of hemodynamic, arterial, echocardiographic and biological parameters to the evaluation of individual cardiovascular risk in the elderly. The study included patients aged over 70 years hospitalized in geriatric units with overt cardiovascular disease. Cross sectional analysis of the first 194 subjects included in the study demonstrated a high rate of arterial alterations involving both structure and function. The principal alterations observed were: high pulse pressure despite normal mean systolic and diastolic pressures, frequent and diffuse arterial calcifications, reduced compliance and distensibility, increased thickness, diameter and incremental elastic modulus of the carotid and increased pulse wave velocity. Analysis of monitoring results in the PROTEGER study will demonstrate the role of hemodynamic measurements and arterial alterations in the prediction of cardiovascular risk in hospitalized elderly.

Circulating relaxin concentrations in pregnant and nonpregnant bitches: evaluation of a new enzymeimmunoassay for determination of pregnancy

A new kit (ReproCHEK RELAXIN) intended for the diagnosis of pregnancy in bitches is now available for veterinary use. This assay measures relaxin concentrations in plasma and whole blood samples, and the presence of significant amounts of relaxin is indicative of pregnancy. A clinical trial was carried out to evaluate the performance of the test. Serial blood samples were collected on alternate days, and relaxin concentrations were determined from day 15 to day 35 after the LH surge (estimated by progesterone concentrations). Pregnancy was confirmed using ultrasonography. At the end of pregnancy, both the day of whelping and the size of the litter were recorded. Pregnancy was established in 61 bitches. The day that pregnancy was detected using the relaxin assay ranged from day 19 to day 28 after the LH surge and had a mean (+/- SD) of 25.4 +/- 2.5 days. The day of parturition was taken as a reference point, and pregnancy was detected from -46 to -38 days (mean -40.2 +/- 2.4 days) before parturition. False positives were not observed in pseudopregnant bitches (n = 16) or in the control group (30 anoestrous and ten unmated bitches). These results demonstrate that the new assay kit is an inexpensive, user-friendly and reliable technique for determining pregnancy.

Taurine and hypotaurine in spermatozoa and epididymal fluid of cats

Taurine and hypotaurine have been found in spermatozoa and seminal plasma of numerous species and are known to have beneficial effects on sperm characteristics in mammals. Taurine is considered an essential dietary constituent in cats. Dietary deficiency has been associated with a range of serious clinical disorders. Quantification of taurine and hypotaurine in the genital tracts of male cats has not been reported. In this study, the concentrations of taurine and its precursors were measured in serum, spermatozoa, epididymal fluid and seminal plasma from cats. The concentrations of taurine measured in serum samples confirmed that the cats were not deficient in taurine. Significant amounts of taurine and hypotaurine were found in spermatozoa, seminal plasma and epididymal flushing fluid. Hypotaurine was not detected in serum samples. These results indicate that hypotaurine may be synthesized in cat testes or epididymides. Cysteamine was not detected in any of the samples.

[Risk factors for multiple intestinal parasites in an indigenous community of the State of Pernambuco, Brazil]

An investigation into the ethno-epidemiological profile of the Pankararu indigenous group in the State of Pernambuco, Brazil, identified multiple intestinal parasites in nearly all members of the community. To detect possible environmental risk factors, we used the data base from a previous survey to test relations between daily living conditions (housing, sanitation, water supply and treatment, and garbage disposal) and the number of different parasite species found in the same household. The sample consisted of 84 families from the original sample of 112. Selection was based on the number of stool tests performed in the family. The mean number of parasite species was 5.0 per family, for a mean family size of 6.1 members. This number was greater for wattle-and-daub houses (mean 6.0 parasite species vs. 4.9 for brick houses; p < 0.03) and when water used in the household was not treated (mean 5.1 parasite species, vs. 4.5 for treated water; p < 0.05). Other household characteristics and hygienic habits did not significantly influence this number. We concluded that multiple intestinal parasitism in the Pernambuco Pankararu community is frequent, to the point of being the rule, and that it relates essentially to water source and treatment.

Changes in cognitive abilities over a 4-year period are unfavorably affected in elderly diabetic subjects: results of the Epidemiology of Vascular Aging Study

OBJECTIVE

To compare 4-year changes in cognitive performance among elderly subjects according to category of fasting blood glucose (FBG) using American Diabetes Association criteria.

RESEARCH DESIGN AND METHODS

Subjects without any detectable cognitive dysfunction were selected from the Epidemiology of Vascular Aging (EVA) Study, a cohort of community-dlwelling people aged 59-71 years at baseline. They were classified into glucose categories (normal, impaired fasting glucose [IFG], or diabetic) based on FBG values or known diabetes. Their cognitive abilities were assessed by a global test (Mini Mental Status Examination [MMSE]) and eight domain-specific tests, and they were reassessed 4 years later. Serious cognitive worsening was defined as a score evolution into the worst 15% of the sample's distribution of score differences (4-year score minus baseline score) for each test.

RESULTS

At baseline, age-, sex-, and education-adjusted scores for all cognitive tests except one were similar across glucose categories. After 4 years, diabetic subjects had a lower performance on all tests except the MMSE, with differences reaching statistical significance on four tests. Adjusted odds ratios for serious worsening over 4 years in diabetic subjects, with reference to normal subjects, were >2 for four tests (P < 0.05) and bordering this value for two others (P < 0.09). Further adjustment for blood pressure or potential cognition-affecting substances (alcohol, tobacco, and medications) did not modify these results.

CONCLUSIONS

Despite similar high initial cognitive function, diabetic subjects tended to have an unfavorable evolution of cognitive performance over 4 years compared with subjects who had normal glucose or IFG.

High plasma nonesterified fatty acids are predictive of cancer mortality but not of coronary heart disease mortality: results from the Paris Prospective Study

To assess the association of fasting plasma nonesterified fatty acid (NEFA) concentration with the risk of death from coronary heart disease and cancer, the authors computed 15-year mortality rates for the 4,589 working men aged 43-53 years who were included in the Paris Prospective Study between 1967 and 1972. A total of 251 and 126 men died from cancer and coronary heart disease, respectively. For coronary heart disease death, the age- and tobacco-adjusted relative risk for men in the highest 20% of the fasting plasma NEFA concentrations compared with those in the lowest 80% was 1.54 (95% confidence interval (CI): 1.01, 2.34). It became nonsignificant after further adjustment for blood pressure, iliac/thigh ratio, and plasma insulin and cholesterol concentrations. In contrast, a high fasting plasma NEFA concentration exhibited a strong independent relation with cancer mortality (relative risk = 1.66, 95% CI: 1.25, 2.21, after adjustment for age, cigarette consumption, heart rate, and body mass index). Despite pathophysiologic mechanisms linking NEFA metabolism with visceral fat and plasma glucose, insulin, and triglyceride concentrations, the plasma NEFA concentration does not appear to be a good marker for coronary heart disease risk. In contrast, an unexpected association with cancer mortality was found that may point to the need for further investigation.

In vitro capacitation of dog spermatozoa as assessed by chlortetracycline staining

We developed an assay for detecting capacitation and acrosome status in dog spermatozoa using chlortetracycline (CTC) as a fluorescent probe. Sperm cells were stained after incubation in modified canine capacitation medium (mCCM). Calcium ionophore A23187 permitted the induction of acrosomal exocytosis of capacitated sperm cells. Spermac staining and transmission electron microscopy were used as control tests to detect acrosome-reacted spermatozoa. Three different patterns of CTC distribution in the spermatozoa were found. These patterns were similar to those observed in other mammalian species. The CTC test was used to monitor the time course of the capacitation process in dogs. It was found that the kinetics of capacitation in canine sperm cells are similar to those observed in other mammals.

Socio-medical intervention in occupational health: benzenism in Brazil

This review describes the authors' experience with 2,000 cases of benzene poisoning reported between 1983 and 1995 in Cubatão, an industrial section of São Paulo, Brazil, investigated through the integration of epidemiology and clinical research. Conflicting economic interests were reflected in disputes about medical criteria for evaluation of poisoned workers, about proper means of conducting workplace hygiene evaluations, about benzene exposure standards, and about compensation for chronic bone-marrow damage.

Insulin-resistance syndrome and cardiovascular complications of non-insulin-dependent diabetes mellitus

Although most cohort studies have shown that diabetes is a risk factor for cardiovascular disease, the mechanisms remain unclear. Hyperglycaemia defines this disorder but does not provide the criteria for causality. However, there are new indications for the possible role of a potentially atherogenic and diabetogenic syndrome rooted in insulin resistance, which was first described by Reaven as "syndrome X". In its complete form, this syndrome includes hyperinsulinaemia, glucose intolerance, dyslipidaemia, elevated blood pressure and fibrinolytic impairment. The complex pathophysiological processes leading to the clustering of these abnormalities are still unclear but probably relate to excessive intra-abdominal fat deposits (clinically expressed by upper body fet distribution) and combined insulin resistance and hyper-insulinaemia. The presence of insulin resistance and hyperinsulinaemia in pre-diabetic individuals, and their predictive role in non-insulin dependent diabetes mellitus, has been documented in various ethnic groups, suggesting a two-step process in the natural history of the disease, i.e. "compensated" insulin resistance followed by failure of insulin secretory response leading to a hyperglycaemic (diabetic) phase. In Caucasians at least, in whom the insulin-resistance syndrome includes clear abnormalities in its most potentially atherogenic elements, this natural history suggests that the cardiovascular complications associated with non-insulin dependent diabetes mellitus originate from the initial "pre-diabetic" phase of the disease. Early prevention would theoretically require intervention before hyperglycaemia occurs (or even if it will never occur) for all upper body obese subjects who present with insulin-resistance syndrome.

The effect of metformin on the metabolic abnormalities associated with upper-body fat distribution. BIGPRO Study Group

OBJECTIVE

The constellation of anomalies associated with insulin resistance is a plausible additional cause of ischemic cardiovascular disease and of NIDDM. To test this hypothesis in a primary prevention trial, the effects of metformin as a potential candidate for intervention in the insulin resistance syndrome (IRS) were evaluated in 324 middle-aged subjects with upper-body obesity.

RESEARCH DESIGN AND METHODS

Trial patients were selected on the basis of a high waist-to-hip ratio. They were randomly allocated to receive either metformin or placebo, following a double-blind procedure. After 1 year of treatment, the main clinical and biological parameters of the IRS were assessed and their evolution compared between treatment groups.

RESULTS

Compared with placebo, metformin induced a significant weight loss, a better maintenance of fasting blood glucose, total and LDL cholesterol levels, and a greater decrease of fasting plasma insulin concentration. Moreover, tissue-type plasminogen activator antigen, a marker of fibrinolytic impairment, showed a significant decrease under metformin. By contrast, metformin treatment had no significant effect on blood pressure or serum triglyceride and HDL cholesterol concentrations. The main side effect of metformin was diarrhea.

CONCLUSIONS

The BIGuanides and Prevention of Risks in Obesity (BIGPRO1) results suggest that metformin would be a suitable candidate for long-term intervention for the prevention of diabetes but that its use in a trial of primary prevention of cardiovascular diseases requires either a reevaluation of its properties toward the most potentially atherogenic anomalies of the IRS or a better definition of the target population.

Lower survival in AIDS patients receiving dapsone compared with aerosolized pentamidine for secondary prophylaxis of Pneumocystis carinii pneumonia. Study Group

A randomized, unblinded study compared aerosolized pentamidine, 300 mg every month, and dapsone, 50 mg/day, for secondary prophylaxis of pneumocystosis in 196 AIDS patients. The study was prematurely discontinued due to excess mortality in the dapsone group. After a mean follow-up of 13 +/- 6.4 months, 22 (21%) of 103 patients in the pentamidine group were dead compared with 39 (42%) of 93 receiving dapsone; the estimated mortality rates at 18 months were 24.6% and 53.1%, respectively (P < .003, log-rank test). A negative interaction was observed between zidovudine and dapsone (P < .049, interaction test of Cox model), and the mean CD4 cell count during the study was lower in the dapsone (49 +/- 61/mm3) than in the pentamidine group (83 +/- 88/mm3; P < .002, t test). The lower survival might also be related to the oxidative effect of dapsone or to the addition of iron protoxalate to dapsone in this study. These results suggest caution in using dapsone as long-term therapy in advanced human immunodeficiency virus infection, especially in those receiving zidovudine.