Total Hip Bone Mineral Density as an Indicator of Fracture Risk in Bisphosphonate-Treated Patients in a Real-World Setting

Bone mineral density (BMD) is an established measure used to diagnose patients with osteoporosis. In clinical trials, change in BMD has been shown to provide a reliable estimate of fracture risk reduction, and achieved BMD T-score has been shown to reflect the near-term risk of fracture. We aimed to test the association between BMD T-score and fracture risk in patients treated for osteoporosis in a real-world setting. This retrospective, observational cohort study included Swedish females aged ≥55 years who had a total hip BMD measurement at one of three participating clinics. Patients were separated into two cohorts: bisphosphonate-treated and bisphosphonate-naïve prior to BMD measurement, stratified by age and prior nonvertebral fracture status. The primary outcome was cumulative incidence of clinical fractures within 24 months of BMD measurement, with other fracture types included as secondary outcomes. Associations between T-score and fracture risk were estimated using proportional hazards regression and restricted cubic splines. A total of 15,395 patients were analyzed: 11,973 bisphosphonate-naïve and 3422 bisphosphonate-treated. In the 24 months following BMD measurement, 6.3% (95% confidence interval [CI], 5.9-6.7) of bisphosphonate-naïve and 8.4% (95% CI, 7.5-9.4) of bisphosphonate-treated patients experienced a clinical fracture. Strong inverse relationships between BMD T-score and fracture incidence were observed in both cohorts. Among bisphosphonate-naïve patients, this relationship appeared to plateau around T-score -1.5, indicating smaller marginal reductions in fracture risk above this value; bisphosphonate-treated patients showed a more consistent marginal change in fracture risk across the evaluated T-scores (-3.0 to -0.5). Trends remained robust regardless of age and prior fracture status. This real-world demonstration of a BMD-fracture risk association in both bisphosphonate-naïve and bisphosphonate-treated patients extends evidence from clinical trials and recent meta-regressions supporting the suitability of total hip BMD as a meaningful outcome for the clinical management of patients with osteoporosis. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Real-world effectiveness of osteoporosis treatment in the oldest old

We studied effectiveness of osteoporosis treatment in women older than 80 years, who often are not included in clinical trials. Treatments were as effective on bone density and fractures as in younger women.

INTRODUCTION

To study real-world effectiveness of osteoporosis treatment on BMD and fractures in the oldest old women (≥ 80 years) compared with women (60-79 years) in the clinical setting using Swedish health register data.

METHODS

National registers and data from DXA machines were used to study effectiveness of all available osteoporosis treatments in women 60-79 and ≥ 80 years using three approaches: (1) Total Hip BMD change up to 8 years after treatment start; (2) fracture incidence where patients served as their own controls, comparing the first 3 months after treatment start with the subsequent 12 months; and (3) comparison of fracture incidence post-fracture in women ≥ 80 years treated with osteoporosis treatment or calcium/vitamin D.

RESULTS

Analysis 1: Total Hip BMD increased by up to 6.7% and 7.7% in women 60-79 and ≥ 80 years old, respectively. The mean increase in BMD was 1.1%-units per year in both age groups. Analysis 2: Relative to the 3-month baseline, fracture incidence decreased during the subsequent 12 months of treatment. Incidence rate ratios were estimated at 0.65, 0.74, 0.29, and 0.81 for any, hip, vertebral, and non-hip-non-vertebral fracture, respectively. Analysis 3: A 24-month incidence of any fracture in women ≥ 80 years given post-fracture osteoporosis treatment was lower (HR = 0.78) than in women given calcium/vitamin D, but treatment allocation was not random, with lower mortality (HR = 0.51) in patients receiving OP treatment.

CONCLUSIONS

Osteoporosis medication in women > 80 years in clinical practice likely works, and the magnitude of effect is similar to what was estimated in younger women. The choice between osteoporosis treatment and calcium/vitamin D after fracture in women ≥ 80 years is not random but appears associated with the patient's health status and presence of vertebral fractures, rather than the known risk profile of sustaining a fracture at a high age.

Risk of major osteoporotic fracture after first, second and third fracture in Swedish women aged 50 years and older

BACKGROUND

Osteoporosis affects approximately one in five European women and leads to fragility fractures, which result in poor health, social and economic consequences. Fragility fractures are a strong risk factor for subsequent major osteoporotic fracture (MOF), with risk of MOF being elevated in the 1-2 years following an earlier fracture, a concept described as "imminent risk". This study examines risk of subsequent MOF in patients with one, two or three prior fractures by age and type of fracture.

METHODS

In this retrospective, observational cohort study, Swedish women aged ≥50 years with ≥1 any clinical fragility fracture between July 1, 2006 and December 31, 2012 were identified from Sweden's National Patient Register. Each patient was age- and sex-matched to three controls without history of fracture. Group 1 women included those with one fragility fracture during the study period; Group 2 included those with two fragility fractures; and Group 3 included those with three fragility fractures. "Index fracture" was defined as the first fracture during the study period for Group 1; the second for Group 2; and the third for Group 3. Patients in each cohort and matched controls were followed for up to 60 months or until subsequent MOF (hip, vertebra, forearm, humerus), death or end of data availability.

RESULTS

231,769 women with at least one fracture were included in the study and therefore constituted Group 1; of these, 39,524 constituted Group 2 and of those, 7656 constituted Group 3. At five years, cumulative incidence of subsequent MOF was higher in patients with a history of fracture as compared to controls (Group 1: 20.7% vs 12.3%; Group 2: 32.0% vs 15.3%). Three-year cumulative incidence for Group 3 was 12.1% (vs 10.7% for controls). After adjusting for baseline covariates, risk of subsequent MOF was highest within 0-24 months following an index fracture, then decreased but remained elevated as compared to controls. Having two prior fractures, vertebral fractures and younger age at time of index fracture were associated with greater relative risk.

CONCLUSIONS

Women with a history of osteoporotic fracture are at increased risk of subsequent fracture, which is highest during the first 24 months following a fracture. Younger women and those with vertebral fractures are at greatest relative risk, suggesting that treatment should target these patients and be timely enough to impact the period of imminent risk.

Differing impact of clinical factors on the risk of fracture in younger and older women in the general population and an osteoporosis clinic population

This study assesses the impact of risk factors for fracture in women aged 80+ and 60-79. The results suggest that risk assessment which fits younger women may not be suited for the 80+ strata as many common risk factors are less predictive in the older compared to the younger cohort.

PURPOSE

This study assesses whether the impact of classical risk factors for fracture due to osteoporosis is different in women aged 80+ and women aged 60-79. Since most prior research on the contribution of risk factors is based on patients below 80 years of age, this study aims to fill this knowledge gap to increase the accuracy of risk assessment in the oldest old.

METHODS

Retrospective, observational cohort study using Swedish national health register data and BMD data from osteoporosis clinics. Women aged at least 60 were identified from a random sample of the general population and from the BMD databases and allocated to two populations representing patients at different stages of risk assessment. The relative impact of risk factors on fracture risk was assessed using multivariate competing risk regression with fracture as outcome and death as competing event.

RESULTS

A total of 163,329 women were included from the general population (52,499 aged 80+) and 22,378 from the BMD databases (4563 aged 80+). The clinical risk factors with relatively highest effect on fracture risk in the older patients were prior fracture and hip T-score below - 2.5 SD. Other included risk factors showed lower impact in the older compared to the younger strata.

CONCLUSIONS

This study confirms our understanding of the key risk factors for fracture: age, prior fracture, and a low T-score. Regarding remaining risk factors, risk assessment which fits younger women may not be suited for the 80+ strata as many common risk factors are less predictive in the older compared to the younger cohort.

Risk of imminent fracture following a previous fracture in a Swedish database study

This study examined the imminent risk of a future fracture within 1 and 2 years following a first fracture in women aged 50 years and older and assessed independent factors associated with risk of subsequent fractures. The study highlights the need to intervene rapidly after a fracture to prevent further fractures.

INTRODUCTION

This study aims to determine the imminent risk of subsequent fractures within 1 and 2 years following a first fracture and to assess independent factors associated with subsequent fractures.

METHODS

Retrospective, observational cohort study of women aged ≥ 50 years with a fragility fracture was identified from Swedish national registers. Clinical/demographic characteristics at the time of index fracture and cumulative fracture incidences up to 12 and 24 months following index fracture were calculated. Risk factors for subsequent fracture were identified using multivariate regression analysis.

RESULTS

Two hundred forty-two thousand one hundred eight women (mean [SD] age 74 [12.5] years) were included. The cumulative subsequent fracture incidence at 12 months was 7.1% (95% confidence interval [CI], 6.9-7.2) and at 24 months was 12.0% (95% CI, 11.8-12.1). The rate of subsequent fractures was highest in the first month (~ 15 fractures per 1000 patient-years) and remained steady between 4 and 24 months (~ 5 fractures/1000 patient-years). Higher age was an independent risk factor for imminent subsequent fractures (at 24 months, sub-distribution hazard ratio [HR], 3.07; p < 0.001 for women 80-89 years [reference 50-59 years]). Index vertebral fracture was a strong independent risk factor for subsequent fracture (sub-distribution HR, 2.72 versus hip fracture; p < 0.001 over 12 months; HR, 2.23; p < 0.001 over 24 months).

CONCLUSIONS

Our findings highlight the need to intervene rapidly after any fragility fracture in postmenopausal women. The occurrence of a fragility fracture provides healthcare systems with a unique opportunity to intervene to reduce the increased risk of subsequent fractures.

Toe brachial index in middle aged patients with diabetes mellitus type 2: not just a peripheral issue

AIM

To explore risk factors for peripheral arterial disease (PAD) as well as the association between toe blood pressure and subclinical and clinical central vascular disease in patients with type 2 diabetes.

METHOD

Toe brachial index (TBI) was cross-sectionally analyzed in 742 middle-aged (54-66 years) patients with type 2 diabetes as well as non-diabetic controls and related to other vascular measures (e.g. carotid intima media thickness (IMT), presence of carotid plaque, central arterial stiffness and left ventricular mass index) and previous cardiovascular events.

RESULTS

A TBI ≤ 0.7 was seen in 22% of the patients but only one patient had severe TBI reduction (TBI ≤ 0.3). The corresponding figures in the controls were 13% and 0%, respectively. Mean TBI was significantly lower in patients with type 2 diabetes than in controls (0.81 ± 0.14 vs. 0.87 ± 0.15, p<0.001). In patients with diabetes, a lower TBI was associated with increased central arterial stiffness (p<0.001), IMT (p<0.001) and carotid plaque (p<0.001) as well as with decreasing glomerular filtration rate (p<0.001). Lower TBI was found in patients with previous macrovascular ischemic events. Furthermore, TBI was negatively correlated with age (p<0.001), diabetes duration (p<0.001) and HbA1c (p=0.01).

CONCLUSION

PAD, assessed with TBI, is common in a Swedish middle-aged diabetes type 2 cohort, affecting about one-fifth. As ankle pressure may be confounded by falsely high values in patients with diabetes due to media calcification we conclude that information about TBI may improve the risk evaluation regarding arteriosclerotic disease in both small and large vessels in type 2 diabetes.

Low prevalence of anemia in inflammatory bowel disease: a population-based study in Sweden

OBJECTIVE

Anemia is a well-known complication of inflammatory bowel disease (IBD) with a reported prevalence of 8.8-73.7%. However, knowledge is sparse about the anemia prevalence in a population-based cohort of patients affected by IBD.

MATERIALS AND METHODS

The aim of this retrospective, descriptive, population-based study was to determine and analyze the prevalence of anemia for ambulatory (n = 485) as well as for hospitalized patients diagnosed with IBD in 2008 in the Highland Health Care District, Jönköpings County, Sweden.

RESULTS

The prevalence of anemia at the annual follow-up in the studied IBD population was 6%, 5% for patients with ulcerative colitis (UC), and 9% for those with Crohn's disease (CD). There was a higher rate of anemia at the yearly check up in patients requiring inpatient care during the year. IBD patients, prescribed anti-TNF-α treatment, had a higher rate of anemia. Of the hospitalized UC and CD patients (n = 31), 35% and 50%, respectively, had anemia at admission and 6% and 4% had severe anemia (Hb <100 g/L), respectively.

CONCLUSIONS

The prevalence of anemia in this population was lower than reported previously, probably due to inclusion of all IBD patients in the area in combination with a proactive follow-up model. The prevalence of anemia in this IBD population was similar to the prevalence in the general population. This may indicate that efforts by health care professionals to prevent, identify, and treat anemia in the IBD population have been successful.

Traditional treatment of mental disorders in rural Ethiopia

BACKGROUND

Mental disorders are known to be as prevalent in Ethiopia as in other countries. Only 26 psychiatrists are working in the country with close to 80 million inhabitants. To this should be added clinics run by psychiatric nurses in most of the general hospitals. This means that still most of the mentally ill in the country are trected and cared for in a traditional way.

OBJECTIVES

This paper presents the situation regarding traditional treatment of mental illness in a rural area in central Ethiopia, Butajira, with a population of about 350,000 persons, predominantly Muslim.

METHODS

All traditional healers in Butajira area were mapped by asking key informants. Twenty-four healers were so identified and interviewed about their perception of mental illness and the treatment they offer. Clients from the healers and patients from the local health centre were interviewed about their opinions on the service given.

FINDINGS

A majority of both clients and patients were satisfied with the consultation, but the clients of the healers were more satisfied than the patients in health centres.

CONCLUSION

As most persons with mental disorders are treated by traditional healers in rural Ethiopia and in most other developing countries it is important to do more comprehensive studies on the traditional treatment and to find ways of collaboration between traditional practice and modern medicine.

Improved population-based care: Implementing patient-and demand-directed care for inflammatory bowel disease and evaluating the redesign with a population-based registry

The gastroenterology unit at the Höglands Hospital in Eksjö is responsible for the care of all 466 patients with inflammatory bowel disease (IBD) in a geographic area including approximately 115,000 inhabitants. In 2000, the frustration over an inadequate traditional outpatient clinic inspired us to redesign our outpatient unit to become more patient and demand directed. The redesign included the following: A direct telephone line for patients to a specialized nurse, available during working hours; appointments were scheduled in accordance with expected needs, and emergency appointments were available daily; traditional follow-ups of IBD patients were replaced by an annual telephone contact with a specialized nurse; the team agreed on a patient-centered value base for its work, and the redesign was monitored using clinical outcome measures reflecting 4 dimensions (see parentheses below) of the care in a "Value compass"; quality of life (functional) and routine blood samples (clinical) were followed yearly and collected in a computerized IBD registry together with basic information about the patients; access and waiting lists together with patient satisfaction (satisfaction) are followed regularly; and ward utilization (financial) was registered. Our study shows that the new design offers a more efficient outpatient clinic in which waiting lists are markedly reduced although production rates remains the same. Utilization data show a significant decrease in comparison with national data, showing that the new care is economically favorable. The clinical results regarding anemia frequency in the IBD population are highly comparable with or even better than those found in the literature. We also show good results regarding quality of life where more than 88% of patients achieve set goals. In conclusion, our new patient- and demand-directed care seems to be more efficient and with clinical and quality-of-life results remaining on a high standard.

Gastric emptying in animal models of human diabetes: correlation to blood glucose level and gut neuroendocrine peptide content

Gastric emptying was measured in non-obese diabetic (NOD) and in obese diabetic mice. The feces were collected and the water content was determined. The neuroendocrine peptides known to regulate gastrointestinal motility, namely secretin, gastric inhibitory peptide (GIP), motilin, somatostatin, peptide YY (PYY), substance P, vasoactive intestinal polypeptide (VIP) and galanin, were measured in tissue extracts of different segments of the gut by radioimmunoassay. Whereas the gastric emptying of NOD mice was significantly slower than that of controls, that of the obese diabetic mice was unaltered. The gastric emptying of NOD mice, but not that of obese diabetic mice, correlated with the blood glucose level. The feces weight and water content in NOD mice was significantly higher than controls. The feces water content in obese diabetic mice was significantly lower than that of controls. The concentrations of antral somatostatin, VIP and galanin, and duodenal secretin as well as jejunal motilin in NOD mice were higher than those of controls. Duodenal GIP and colonic PYY concentration in NOD mice was lower than controls. Duodenal GIP and VIP, and colonic somatostatin and VIP levels were lower in obese diabetic mice than controls. Secretin and motilin levels correlated with gastric emptying in NOD mice. The high duodenal concentration of secretin might reflect high synthesis and release of this hormone, and may therefore be among the factors that caused slow gastric emptying in the NOD mice. The increase in concentration of motilin observed in NOD mice may be caused by impaired release of this hormone as a result of hyperglycemia. Whereas the high concentrations of antral VIP and galanin and the low level of colonic PYY in diabetic NOD mice may contribute to the development of diarrhea in NOD mice, the decreased levels of duodenal and colonic VIP and colonic somatostatin in obese diabetic mice may account for the constipation encountered in these animals.

Effect of diabetic state on co-localization of substance P and serotonin in the gut in animal models

Changes in the numbers of serotonin- and substance P-immunoreactive (IR) cells occur in several animal models of diabetes. It is not known, however, whether these changes are a result of actual cell loss or are caused by modified gene expression in cells showing co-localization of serotonin and substance P. The pattern of mono- and co-expression of serotonin, as well as of substance P, was therefore investigated in gastrointestinal endocrine cells from animal models of human type 1 and type 2 diabetes, namely non-obese diabetic (NOD) and obese diabetic (ob/ob) mice. Immunocytochemical staining by the avidin-biotin complex method was performed for computerized image analysis of each cell type, and by immunofluorescence double staining to study co-localization. Tissues from antrum, proximal duodenum and distal colon were investigated. Co-localization of serotonin- and substance P-IR was found in all investigated parts of the gut. In antrum, substance P immunoreactivity was found exclusively in serotonin-IR cells. In both NOD and ob/ob mice there was a reduced number of substance P-IR cells, but an unchanged serotonin-IR cell count, which thus tallies with a shut-off of substance P expression in antral enterochromaffin cells. In duodenum, both diabetes models showed a decreased number of serotonin-IR cells. Furthermore there was a decreased number of substance P-IR cells in the type 2 model. The proportion of serotonin-IR cells showing substance P-immuno-reactivity was decreased in both diabetic models, thus indicating a shut-off of substance P-gene expression. However, this does not fully explain the changes in duodenum, but the diabetic state probably affects the number of mono-expressed cells as well. In colon, no change was found in diabetic mice regarding co-localization of substance P and serotonin. However, pre-diabetic NOD mice showed a decreased proportion of substance P in serotonin-IR cells, which might be explained by the increased number of serotonin-IR cells, combined with an unchanged number of substance P-IR cells. In conclusion, diabetic animal models of both type 1 and type 2 appear to have a combination of decreased expression of substance P in serotonin-IR cells of both antrum and duodenum, as well as a change in the number of mono-expressed cells. The pattern in colon, on the other hand, seems to be unaffected.

Myenteric plexus of obese diabetic mice (an animal model of human type 2 diabetes)

The myenteric plexus of the gastrointestinal tract was investigated in the obese diabetic mouse, an animal model of human type 2 diabetes. Sections were immunostained by the avidin-biotin complex method, using a general nerve marker, protein gene product 9.5 (PGP 9.5), as well as antibodies to several important neurotransmitters. Computerized image analysis was used for quantification. When diabetic mice were compared with controls, no difference was found in the density of PGP 9.5-immunoreactive (IR) nerve fibres in antrum, duodenum or colon. In antrum and duodenum, diabetic mice showed a decreased number of vasoactive intestinal peptide (VIP)-IR neurons in myenteric ganglia as well a decreased relative volume density in myenteric plexus (though not significantly in antrum, p=0.073). No difference was found regarding VIP-IR nerves in colon. The volume density of nitric oxide synthase (NOS)-IR nerve fibres was decreased in antrum and duodenum of diabetic mice, whereas no difference was found in colon. The density of galanin-IR nerve fibres was decreased in duodenum. Whereas neuropeptide Y (NPY)- and vesicular acetylcholine transporter (VAChT)-IR nerve fibres was increased in density in colon of diabetic mice, no difference was found in antrum and duodenum. Regarding substance P, there was no difference between diabetic and control mice in antrum, duodenum or colon. The present study shows that gut innervation is affected in this animal model of human type 2 diabetes. It is possible that the present findings may have some relevance for the gastrointestinal dysfunctions seen in patients with type 2 diabetes.

Diabetic state affects the innervation of gut in an animal model of human type 1 diabetes

Gastrointestinal symptoms in diabetic patients are commonplace, and are believed to be due, at least partly, to neuropathy of the gut. In the present study, therefore, some important neurotransmitters in the myenteric plexus were investigated in non-obese diabetic mice, an animal model of human type 1 diabetes. For this purpose, immunocytochemistry was applied on sections from antrum, duodenum and colon, subsequently quantified by computerized image analysis. Whereas the number of vasoactive intestinal peptide (VIP)-positive neurons was increased in antral myenteric ganglia of diabetic mice, there was a decreased density of nerve fibres in muscularis propria. No difference was seen in the VIP of duodenum and colon. Acetylcholine-containing nerve fibres showed an increased volume density in muscularis propria of antrum and duodenum, but a decreased density in colon of diabetic mice, as compared with controls. There was a decreased number of neurons containing nitric oxide synthase (NOS) in myenteric ganglia of antrum and duodenum. No difference was seen in density of NOS-containing nerve fibres in muscularis propria. There was no difference regarding neuropeptide Y (NPY) and galanin between diabetic and control mice; nor was there any difference between pre-diabetic NOD mice and controls regarding all bioactive substances investigated. It is concluded that the diabetic state affects the innervation of gut in this animal model. The present findings may be of some relevance to the gastrointestinal symptoms seen in patients with diabetes.

Does diabetic state affect co-localization of peptide YY and enteroglucagon in colonic endocrine cells?

BACKGROUND

Changes in the numbers of PYY- and enteroglucagon-immunoreactive cells in colon of animal models of human diabetes have been reported. As these peptides co-localize in the same cells it is possible that the observed changes are a result of changes in co-localization.

METHODS

Animal models of human type 1 and type 2 diabetes, namely the non-obese diabetic (NOD) mouse and the obese (ob/ob) mouse, were studied. As controls for the NOD mice, BALB/cJ mice were used and for ob/ob mice, homozygous lean (+/+) mice were used. Tissue samples from colon were double-immunostained for PYY and enteroglucagon according to the indirect immunofluorescence method.

RESULTS

Co-localization of enteroglucagon and PYY was found in colonic endocrine cells in all groups investigated. Compared with controls, pre-diabetic NOD mice showed a decreased proportion of enteroglucagon/PYY co-localization. There was no difference in diabetic NOD mice or diabetic ob/ob mice when compared with controls.

CONCLUSIONS

Whereas the number of cells containing solely enteroglucagon and solely PYY increases in pre-diabetic NOD mice, production of enteroglucagon in PYY-immunoreactive cells decreases. Although the numbers of PYY and enteroglucagon cells have been reported to be changed in both diabetic NOD mice and in obese mice, the balance between co-expressing and mono-expressing cells seems to be preserved.

Prevalence of gastrointestinal symptoms in young and middle-aged diabetic patients

BACKGROUND

Gastrointestinal disorders have been reported in patients with diabetes mellitus. The present investigation was carried out to evaluate the frequency of gastrointestinal symptoms in out-clinic diabetic patients in the county of Umeå, Sweden.

METHODS

Diabetic patients aged 24-59 years residing in Umeå County (population, 136,000) were included in the study (n = 489), as were 200 sex- and age-matched healthy controls. A questionnaire was mailed to the patients and controls, and a reminder was sent 5 months later. The questionnaire contained 28 questions concerning gastrointestinal symptoms, bowel habits, and medication during the preceding year.

RESULTS

Fifty-nine per cent of the patients and 53% of the controls responded. The total number of reported gastrointestinal symptoms was significantly greater in patients (1.25 +/- 0.10; mean +/- standard deviation) than in control subjects (0.50 +/- 0.08). This increase was seen in both type-1 (1.12 +/- 0.11) and type-2 (1.52 +/- 0.25) diabetic patients. Female diabetic patients reported significantly more symptoms than did male patients (1.59 +/- 0.17 and 0.81 +/- 0.12, respectively). Patients with neuropathy had significantly more symptoms than the other patients. Symptom frequency was not correlated with nephropathy or retinopathy or with the duration of diabetes, body mass index, glycosylated haemoglobin, or insulin dose. Heartburn, constipation, and nocturnal urge to defecate were significantly more frequent in patients than in controls. Furthermore, a feeling of incomplete defecation, a need to strain at defecation, and urgency were significantly more common in patients.

CONCLUSION

Diabetic patients had more gastrointestinal symptoms than non-diabetic population. These symptoms did not correlate with duration of the disease, metabolic control, or any other complication except neuropathy. Heartburn and constipation were among the symptoms that occurred more frequently in diabetic patients than in the non-diabetic population.

Gastrointestinal endocrine cells in an animal model for human type 2 diabetes

Endocrine cells were investigated in various parts of the gastrointestinal tract in an animal model for human type 2 diabetes, namely the homozygous obese mouse. As controls, age- and sex-matched homozygous lean mice were used. The different endocrine cell types were stained by using immunocytochemistry and quantified by computerized image analysis. The numbers of PYY- and enteroglucagon-immunoreactive (IR) cells were decreased in the colon of obese diabetic mice vis-à-vis controls. Serotonin-IR cells were significantly decreased in numbers in the duodenum and colon. Furthermore, colonic serotonin cells had a high cell secretory index (CSI), but an unchanged nuclear area, indicating an impaired cellular release of this amine. There was no statistical difference between obese diabetic mice and lean controls regarding the numbers and CSI of antral gastrin/CCK-, somatostatin- and serotonin-; and duodenal secretin-, gastric inhibitory peptide (GIP)-, CCK/gastrin-, and somatostatin-IR cells; nor was there any difference regarding nuclear area, with the exception of the antral somatostatin- and duodenal GIP-IR cells. It is concluded that the abnormalities in gut endocrine cells observed in the present study might explain the gut dysmotility reported in animal models for human diabetes. They may also be of importance in gastrointestinal dysfunction occurring in diabetes patients.

Large intestinal endocrine cells in non-obese diabetic mice

Colonic endocrine cells from prediabetic and diabetic non-obese diabetic mice as well as of the sister strain, BALB/cJ, were investigated by immunocytochemistry and computer image analysis. In prediabetic mice, enteroglucagon-and serotonin-immunoreactive cells were significantly increased in number, whereas the cell secretory index of these two cell types was significantly reduced. No significant differences were found in numbers or cell secretory index of peptide YY (PYY)-immunoreactive cells. In diabetic mice, PYY-immunoreactive cells were significantly fewer, but there were no significant differences in the numbers of enteroglucagon-and serotonin-immunoreactive cells. Whereas the cell secretory index was reduced in serotonin-producing cells, no significant differences were found between diabetic and control mice regarding the cell secretory index of PYY- and enteroglucagon-immunoreactive cells. Nor was any statistically significant difference found between controls, prediabetic and diabetic non-obese diabetic mice, regarding the thickness of submucosa, of circular and longitudinal-muscle layers, or of the mucosal area/microm baseline. The present study showed that abnormalities in colonic endocrine cells do occur, in both prediabetic and diabetic mice, but they are different in nature and can be divided into primary and secondary to the diabetes onset. The present findings of abnormal colonic endocrine cells in non-obese diabetic mice, an animal model for human insulin-dependent diabetes mellitus, might help explain the gastrointestinal disorders observed in patients with diabetes. The study also showed that the change in the colonic endocrine cells is dynamic and started before the onset of the diabetic condition.

Myenteric plexus in the gastrointestinal tract of non-obese diabetic mice

The myenteric plexus was investigated in the gastrointestinal tract of pre-diabetic and diabetic non-obese diabetic (NOD) mice. The plexus was immunostained by the avidin-biotin complex method, using a general marker for nerve elements, namely protein gene-product 9.5. The nerve fibres were quantified by point-counting and the number of ganglia and their area were determined by image analysis. The relative volume density of the nerve fibres in duodenal muscularis propria was found to be significantly reduced in of both pre-diabetic and diabetic NOD mice. There was no statistical difference between controls and NOD mice regarding relative volume density of nerve fibres in antral and colonic muscularis propria. The number of myenteric ganglia/mm baseline was significantly decreased in the duodenum of diabetic NOD mice, and showed a non-statistically significant tendency to decrease in pre-diabetic mice. In the antrum and colon, there was no difference between the controls and NOD mice regarding the number of ganglia/mm baseline. Nor was there any significant difference between controls and NOD mice in the area of myenteric ganglia in either antrum, duodenum or colon. It is concluded that the changes in the duodenal myenteric plexus of NOD mice are prior to the onset of diabetes. It is suggested that the absence of changes in the antral and colonic myenteric plexus when using a general marker for neuroelements does not preclude a possible change in cholinergic, adrenergic or peptidergic innervation.

Abnormalities of small intestinal endocrine cells in non-obese diabetic mice

The endocrine cells in the duodenum of pre-diabetic and diabetic female non-obese diabetic (NOD) mice aged 22-24 weeks were studied by means of immunohistochemistry and computed image analysis as well as by radioimmunoassays of tissue extracts. As controls, 12 female BALB/cJ mice of the same age as NOD mice were used. The number of secretin-immunoreactive cells increased in diabetic but not in pre-diabetic NOD mice. The level of extractable secretin was higher in both pre-diabetic and diabetic NOD mice. The number of GIP-, CCK/gastrin-, and serotonin-immunoreactive cells was significantly reduced in both pre-diabetic and diabetic NOD mice. There was no statistical difference in the number of somatostatin-immunoreactive cells between the NOD mice and controls. The level of GIP was higher and gastrin was lower in NOD mice compared to controls. There was no statistical difference in the somatostatin level between the NOD mice and controls. The cell secretory index was elevated in all the endocrine cell types except CCK/gastrin cells. It has been suggested that some of the changes in the duodenal endocrine cells could be attributed to the diabetes state, but most of the changes seem to take place before the onset of diabetes. The abnormalities in the duodenal endocrine cells observed here in an animal model for diabetes type I might have relevance for the gastrointestinal dysfunction displayed in human diabetes.

Antral endocrine cells in nonobese diabetic mice

The antral endocrine cells were investigated in nonobese diabetic (NOD) mice by means of immunohistochemistry, image analysis, and radioimmunoassays (RIA). As controls BALB/CJ mice of the same age and sex as the NOD mice were used. The number of gastrin- and somatostatin-immunoreactive cells was significantly decreased in both prediabetic and diabetic mice. There was no statistical difference between the NOD mice and controls regarding the serotonin-immunoreactive cells. Somatostatin levels as revealed by RIA in the antrum of both prediabetic and diabetic NOD mice were lower than those of the controls. There was no statistical difference in the level of antral gastrin between NOD mice and the controls. It was concluded that the changes in antral cells are primary to the onset of diabetes, and that the abnormalities observed in the antral cells in an animal model for diabetes type I might have relevance for the upper gastrointestinal dysfunction displayed in human diabetes.

Neuropeptide contents in the duodenum of non-obese diabetic mice

Twelve pre-diabetic and 12 diabetic female NOD mice aged 22-24 weeks were studied. As controls, 12 female BALB/cJ of the same age and sex were used. The duodenal content of several neuropeptides, namely vasoactive intestinal polypeptide (VIP), neurotensin, neuropeptide Y (NPY), galanin, gastrin-releasing peptide (GRP) and enkephalin was determined by radioimmunoassay of tissue extracts. The VIP content in duodenal extracts from both pre-diabetic and diabetic NOD mice was significantly higher than that of the controls. The enkephalin content of the duodenum of diabetic mice was significantly higher than that of the controls, while no significant difference was found between the controls and pre-diabetic mice. There was no statistically significant difference between controls and NOD mice regarding the duodenal content of neurotensin, NPY, galanin or GRP. It has been suggested that the high duodenal content of VIP appears to be primary to the onset of diabetes and that the high enkephalin content may be attributable to the diabetic state. The changes in the duodenal content of VIP and enkephalin reported here in an animal model for diabetes type I might be of relevance for the gastrointestinal complications occurring in human diabetes.

Substance P in the gastrointestinal tract of non-obese diabetic mice

BACKGROUND

Gut dysmotility occurs in most diabetics. Substance P is a neurotransmitter that plays an important role in regulating gastrointestinal motility. The present investigation was carried out to evaluate the possible role of this neurotransmitter in the pathogenesis of dysmotility in diabetics.

METHODS

Pre-diabetic and diabetic female non-obese diabetic (NOD) mice aged 22-24 weeks were studied. As controls, BALB/CJ mice of the same age and sex were used. Substance P concentrations in tissue extracts from the antrum, duodenum, and colon were determined with radioimmunoassay. Substance P-immunoreactive nerve elements and endocrine cells were identified by immunocytochemistry and quantified with computerized image analysis.

RESULTS

Substance P levels in the antrum of both pre-diabetic and diabetic NOD mice were significantly lower than those of controls. In the duodenum and colon substance P levels were higher than those of the controls in both pre-diabetics and diabetic NOD mice. The relative volume density of substance P-immunoreactive nerve fibres in the colon of diabetic NOD mice was significantly decreased. There was no statistically significant difference between pre-diabetic and diabetic NOD mice and controls with regard to the relative volume density of substance P immunoreactive nerve fibres in the antrum and duodenum. In the antrum the number of substance P-immunoreactive cells decreased significantly in both pre-diabetic and diabetic NOD mice. In the duodenum and colon the numbers of these cells in NOD mice did not differ from those of controls.

CONCLUSIONS

The changes in substance P contents in various parts of the gastrointestinal tract of NOD mice seem to be primary to the onset of diabetes. The decreased antral substance P contents in NOD mice seems to be caused by structural change in the mucosal endocrine cells. In the small and large intestine the increase in substance P levels appears to be caused by change in the physiologic activities of the nerve element and/or endocrine cells rather than by structure changes. The abnormalities observed here in an animal model for diabetes type I might have relevance for the gastrointestinal dysmotility displayed in human diabetes.