Limited joint mobility in subjects with insulin dependent diabetes mellitus: relationship with eye and kidney complications

Update on NKCC2 regulation in the thick ascending limb (TAL) by membrane trafficking, phosphorylation, and protein-protein interactions

Purpose of review

The thick ascending limb (TAL) of loop of Henle is essential for NaCl, calcium and magnesium homeostasis, pH balance and for urine concentration. NKCC2 is the main transporter for NaCl reabsorption in the TAL and its regulation is very complex. There have been recent advancements toward understanding how NKCC2 is regulated by protein trafficking, protein-protein interaction, and phosphorylation/dephosphorylation. Here, we update the latest molecular mechanisms and players that control NKCC2 function, which gives an increasingly complex picture of NKKC2 regulation in the apical membrane of the TAL.

Recent Findings

Protein-protein interactions are required as a regulatory mechanism in many cellular processes. A handful of proteins have been recently identified as an interacting partner of NKCC2, which play major roles in regulating NKCC2 trafficking and activity. New players in NKCC2 internalization and trafficking have been identified. NKCC2 activity is also regulated by kinases and phosphatases, and there have been developments in that area as well.

Summary

Here we review the current understanding of apical trafficking of NKCC2 in the thick ascending limb (TAL) which is tightly controlled by protein-protein interactions, protein turnover and by phosphorylation and dephosphorylation. We discuss new proteins and processes that regulate NKCC2 that have physiological and pathological significance.

The Relationship Between Hand Abnormalities and Diabetic Retinopathy in Patients with Type 2 Diabetes Mellitus

Background: The link between diabetes mellitus (DM) and pathological conditions of the hand has been previously investigated. Retinopathy is one of the most common microvascular complications of DM. In this study, we aimed to evaluate the relationship between hand abnormalities and retinopathy in patients with type 2 DM. Methods: Patients with type 2 DM were assessed for hand abnormalities using tactile, functional, and sensory tests. The patients were evaluated electrodiagnostically for carpal tunnel syndrome and polyneuropathy (PNP). A comprehensive ophthalmologic examination was performed to diagnose diabetic retinopathy (DR). Subjective disability and quality of life were evaluated using the Quick DASH questionnaire. The duration of the disease and HbA1c levels were noted. Results: A total of 60 patients with type 2 DM (32 female, 28 male) were recruited for this study. The mean age was 55.1 ± 5.6 years. Among the 60 diabetic patients examined, 15 (25%) were diagnosed with DR. The mean duration of DM was 86.86 ± 51.69 months in patients without DR and 144.75 ± 82.96 months in patients with DR. The mean HbA1c level was 8.86% in the DR group and 8.64% in the non-DR group. PNP was the only hand abnormality that showed a significant association with retinopathy (p = 0.011). Conclusions: PNP might be used as a clue to the presence of retinopathy, especially in long-lasting diabetes. Particular attention should be given to hand abnormalities, especially in patients with PNP, due to their association with DR.

Quantification of joint mobility limitation in adult type 1 diabetes

Aims

Diabetic cheiroarthropathies limit hand mobility due to fibrosis and could be markers of a global profibrotic trajectory. Heterogeneity in definitions and lack of a method to measure it complicate studying associations with organ involvement and treatment outcomes. We measured metacarpophalangeal (MCP) joint extension as a metric and describe magnetic resonance (MR) imaging determinants of MCP restriction.

Methods

Adults with type 1 diabetes were screened for hand manifestations using a symptom questionnaire, clinical examination, and function [Duruoz hand index (DHI) and grip strength]. Patients were segregated by mean MCP extension (<20°, 20°-40°, 40°-60°, and >60°) for MR imaging (MRI) scanning. Patients in the four groups were compared using ANOVA for clinical features and MRI tissue measurements (tenosynovial, skin, and fascia thickness). We performed multiple linear regression for determinants of MCP extension.

Results

Of the 237 patients (90 men), 79 (33.8%) with cheiroarthropathy had MCP extension limitation (39° versus 61°, p < 0.01). Groups with limited MCP extension had higher DHI (1.9 vs. 0.2) but few (7%) had pain. Height, systolic blood pressure, and nephropathy were associated with mean MCP extension. Hand MRI (n = 61) showed flexor tenosynovitis in four patients and median neuritis in one patient. Groups with MCP mobility restriction had the thickest palmar skin; tendon thickness or median nerve area did not differ. Only mean palmar skin thickness was associated with MCP extension angle on multiple linear regression.

Conclusion

Joint mobility limitation was quantified by restricted mean MCP extension and had structural correlates on MRI. These can serve as quantitative measures for future associative and interventional studies.

The Association of Diabetic Cheiroarthropathy With Microvascular Complications of Type 2 Diabetes Mellitus: A Cross-Sectional Study

Introduction Diabetic cheiroarthropathy (DCA), also known as the syndrome of limited joint mobility (LJM), is among the most underdiagnosed complications of diabetes mellitus (DM). Although not severe, it can hamper the day-to-day activities of the patient and significantly reduce the quality of life. It is hypothesized to be due to increased glycation of collagen around joints. The objective of our study was to examine the association of diabetic cheiroarthropathy with microvascular complications of type 2 diabetes mellitus. Methods The study was conducted on 251 previously diagnosed cases of type 2 DM. Patients with previous contractures due to any other cause, who are diagnosed cases of rheumatoid arthritis and scleroderma, and other risk factors such as cardiac or renal disease were excluded from the study. All subjects were subjected to a detailed clinical history including a past history, thorough physical examination, prayer test, tabletop sign, and passive extension of fingers. Patients who are diagnosed with diabetic cheiroarthropathy were then screened for microalbuminuria, fundus examination, and monofilament test and clinical examination to look for the presence of microvascular complications. Results Out of the 251 patients, 46 (18.3%) were found to have diabetic cheiroarthropathy. Fifteen (34.9%) cheiroarthropathy patients had neuropathy compared to 14.9% without diabetic cheiroarthropathy, which was statistically significant. We found that there was an increased incidence of diabetic neuropathy in subjects with cheiroarthropathy. Thirty (35.7%) patients with diabetic cheiroarthropathy had diabetic retinopathy compared to 9.6% without diabetic cheiroarthropathy. Twenty-six (26.8%) patients with diabetic cheiroarthropathy had diabetic nephropathy compared to 13% without diabetic cheiroarthropathy. We identified from our study that patients with diabetic cheiroarthropathy had an increased risk of developing microvascular complications. Conclusion There is an increased prevalence of diabetic nephropathy, diabetic neuropathy, and diabetic retinopathy in patients with diabetic cheiroarthropathy. The presence of diabetic cheiroarthropathy hence warrants better control of the patient's glycemic status to prevent further deterioration of diabetes-related complications.

Juvenile diabetes and systemic sclerosis: just a coincidence?

BACKGROUND

Limited joint mobility (LJM), previously known as cheiroarthropathy, refers to the presence of reduced extension at the finger joints in people with diabetes and may be associated with scleroderma-like syndromes such as diabetic sclerodactyly. While scleroderma-like syndromes and LJM have been observed in patients with long-term diabetes and associated complications, the coexistence of diabetes with Juvenile systemic sclerosis (jSSc) is rarely described.

CASE PRESENTATION

We describe the case of a 14-year-old boy with long-lasting type 1 diabetes (T1D) and suspected LJM associated with Raynaud phenomenon, sclerodactyly and tapering of the fingertips. A comprehensive work-up showed positive autoantibodies (ANA, anti-Ro-52, anti-Mi-2b), abnormal nailfold capillaroscopy with a scleroderma pattern, interstitial lung disease and cardiac involvement. The overall clinical picture was consistent with the diagnosis of jSSc.

CONCLUSIONS

LJM can be the initial sign of underlying systemic sclerosis. Nailfold capillaroscopy may help differentiate jSSc from classical LJM in pediatric patients with T1D and finger contractures or skin induration of no clear origin. This case report provides a starting point for a novel hypothesis regarding the pathogenesis of jSSc. The association between T1D and jSSc may be more than a coincidence and could suggest a relationship between glucose metabolism, fibrosis and microangiopathy.

Limited joint mobility of the hand correlates incident hospitalisation with infection in patients with type 2 diabetes

AIM

Limited joint mobility (LJM) of the hand is one of the important complications of diabetes. Diabetes is a risk factor for hospitalisation with infection. This study investigated the relationship between LJM of the hand and the incidence of hospitalisation with infection in type 2 diabetic patients.

MATERIALS AND METHODS

LJM of hand was defined as the 'prayer sign' or 'table test'. The association between LJM of the hand and incident hospitalisations was evaluated using Cox regression analysis. The number of incident hospitalisations was small over the course of the study, which we compensated for by calculating propensity scores using age, body mass index, sex, duration of diabetes, creatinine, smoking status, haemoglobin A1c and dyslipidaemia.

RESULTS

In this retrospective cohort study of 502 patients with type 2 diabetes, 102 patients had LJM of the hand. These patients were, on average, older and had worse renal function and glycaemic control, and a higher proportion of microangiopathy significantly. During the study period, 56 patients were hospitalised with infection. A Cox regression analysis showed that LJM of the hand was associated with an increased probability of incident hospitalisation with infection after adjustment for covariates (HR = 1.65 [95% CI 1.60-1.70], p < 0.001).

CONCLUSIONS

Our results reveal that LJM of the hand is associated with incident of hospitalisation with infection. A diagnosis of LJM of the hand might, therefore, be a useful indicator for assessing the risk of hospitalisation with infection in type 2 diabetic patients.

History, Prevalence and Assessment of Limited Joint Mobility, from Stiff Hand Syndrome to Diabetic Foot Ulcer Prevention: A Narrative Review of the Literature

BACKGROUND

Limited Joint Mobility (LJM) is a dreaded complication of Diabetes Mellitus (DM). During the last half century, LJM has been studied in patients of different age because it has been considered useful for the monitoring of a patient's condition and for the prevention of vascular disease and diabetic foot.

OBJECTIVES

The main aims of this review are to describe the relationship between DM and joint mobility as well as its prevalence and assessment. We have also investigated the role of LJM in the development of diabetic foot ulcers.

METHODOLOGY

An in-depth literature search was conducted to identify studies that examined the prevalence and characteristics of LJM in patients with DM of different types, age, durations and chronic complications.

RESULTS

Many factors (therapy improvements, population characteristics and different evaluation methods) concur to hinder an exact assessment of the prevalence of LJM. However, it has been confirmed that LJM is widespread among patients with DM and may affect more than two-thirds of them in addition to being a major risk factor for foot ulcer. Its role in the monitoring of a patient's condition is also important for the definition of risk thresholds such as in patients with diabetic foot. The efficacy of exercise therapy for the treatment of LJM, also in patients at risk of foot ulcer, has not been discussed.

CONCLUSION

Difficulties encountered in the definition of the prevalence of LJM may hinder its study and the establishment of preventive interventions. However, LJM plays a key role in the monitoring of patients, especially those at risk for ulcer.

Limited Joint Mobility Progression in Type 1 Diabetes: A 15-Year Follow-Up Study

OBJECTIVE

To assess the evolution of joint mobility over a period of 15 years in type 1 diabetic patients and healthy controls and to determine whether microalbuminuria is associated with a different evolution of joint mobility.

METHODS

Joint mobility of hand and wrist was determined in 63 patients with type 1 diabetes and 63 healthy subjects. Fifteen years later, 37 (58.7%) diabetic patients and 16 (25.4%) healthy subjects were studied again. Joint mobility was assessed with the Prayer sign and by measuring the angle of maximal flexion of the fifth and third metacarpophalangeal (MCP) joints and wrist. Patients with diabetes were visited 2-4 times every year with regular assessment of glycated hemoglobin (HbA1_c), urinary albumin excretion (UAE), and ophthalmoscopy.

RESULTS

Fifteen years after the initial exam, diabetic patients showed reduced flexion of the fifth MCP joint (82.6 ± 5.8 versus 76.0 ± 6.4 degrees, p < 0.001) and wrist (75.9 ± 8.1 versus 73.2 ± 7.4 degrees, p = 0.015) compared to baseline examination. Joint mobility did not change significantly in healthy subjects. Patients with microalbuminuria showed greater reduction in hand joint mobility than diabetic patients with normal UAE or than healthy subjects (p < 0.001).

CONCLUSIONS

In type 1 diabetic patients, the severity of LJM progresses with time, and the progression is enhanced in patients with microalbuminuria.

Prevalence of hand disorders in type 2 diabetes mellitus and its correlation with microvascular complications

Background:

Physicians have long recognized the association between diabetes mellitus and several pathologic conditions of the hand. The most commonly recognized maladies are limited joint mobility (LJM), Dupuytren's disease (DD), trigger finger (TF), and carpal tunnel syndrome (CTS). Incidence of these hand disorders has increased in the setting of diabetes. Collectively, these are described as diabetic hand syndrome.

Aim:

The aims were to find out the prevalence of hand disorders in diabetic patients, and to study the relation of these hand disorders with microvascular complications.

Subjects and Methods:

This is an observational cross-sectional case-control study done over a period of 1 year Patients of type 2 DM, of age < 65 years, who visited Gandhi Memorial Hospital, Lucknow were enrolled and were described as cases. Age- and sex-matched nondiabetic individuals were taken in the control group. The data were analyzed using software SPSS. SPSS Inc. Released 2008. SPSS Statistics for Windows, Version 17.0. Chicago: SPSS Inc. Means and standard deviations were computed; the Student t-test and Chi-square (χ²) test were used as appropriate.

Results:

A total of 400 subjects were studied, 200 each in the case and control groups. Of total 200 diabetic patients, 30% (60/200) patients had neuropathy, 37.5% (75/200) had nephropathy, and 44.5% (89/200) patients had retinopathy. In the study population, 67% patients were having one or more hand disorders, in which LJM was found in 40.5% (81/200) patients, DD was found in 19% (38/200) patients, TF in 16.5% (33/200), and CTS in 14% (28/200) patients.

Conclusions:

This study shows a high prevalence of hand disorders in diabetic patients and also correlates with the duration of type 2 DM, LJM being the most common hand disorder and more common in patients who have microvascular complications.

Diabetes mellitus en niños y adolescentes: complicaciones crónicas y enfermedades asociadas

Diabetes is one of the most common chronic diseases. Type 1, or autoimmune, diabetes accounts for more than 95 % of cases in children and adolescents. Chronic hyperglycemia per se is responsible for the development of several microvascular (retinopathy, nephropathy, neuropathy) and macrovascular complications (ischemic heart disease, cerebrovascular disease, and peripheral vascular disease). Other autoimmune diseases are also more frequent in type 1 diabetic patients. The present review aims to provide an update on some recent advances in this field to aid early detection of these complications and prevent or delay their progression through improved metabolic control.

Longitudinal relation between limited joint mobility, height, insulin-like growth factor 1 levels, and risk of developing microalbuminuria: the Oxford Regional Prospective Study

AIMS

To determine risk factors for development of microalbuminuria (MA) in relation to detection of limited joint mobility (LJM+) of the interphalangeal joints in a longitudinal cohort of type 1 diabetic (T1DM) subjects.

METHODS

A total of 479 T1DM subjects diagnosed <16 years were followed from diagnosis of diabetes with annual assessments consisting of assessment of LJM, measurement of HbA1c and insulin-like growth factor 1 (IGF-1), and three urine samples for albumin:creatinine ratio (ACR).

RESULTS

After a median follow up of 10.9 years, 162 subjects (35.1%) developed LJM at median age 13.0 years and duration 5.2 years. More subjects developed LJM after compared to before puberty (67.6 v 32.4%). In LJM+ compared to LJM- subjects, HbA1c (mean 10.1 (SD 1.6) v 9.6 (1.4) %)) and ACR levels (median 1.1 (range 0.2-242.9) v 0.9 (0.4-70.7) mg/mmol) were higher, and in a Cox model probability of developing LJM was related to puberty and higher HbA1c levels. ACR levels were higher after detection of LJM compared to before (median 1.2 (range 0.4-102.6) v 0.8 (0.2-181.9) mg/mmol). Probability of developing MA was related to puberty, HbA1c, female sex, and presence of LJM (a 1.9-fold increased risk). Both LJM and MA were associated with lower height SDS (LJM: mean 0.0 (SD 1.0) v 0.2 (1.1); MA: 0.0 (1.0) v 0.2 (SD 1.0)) and lower IGF-1 levels.

CONCLUSION

The development of LJM was associated with an increased risk of microalbuminuria, independent of glycaemic control. Risk for both microalbuminuria and LJM was associated with puberty, reduced growth, and reduced IGF-1 levels, and may indicate underlying shared pathogenic mechanisms.

Reduced prevalence of limited joint mobility in type 1 diabetes in a U.K. clinic population over a 20-year period

OBJECTIVE

Limited joint mobility (LJM), one of the earliest clinically apparent long-term complications of type 1 diabetes, is a risk marker for subsequent microvascular complications. We hypothesize that the prevalence of LJM may have decreased during the past two decades due to improved standards of glycemic control.

RESEARCH DESIGN AND METHODS

A single observer performed a survey in 204 consecutive patients with type 1 diabetes (106 men and 98 women, age 27 +/- 1 years, HbA(1c) 8.3 +/- 0.1%, duration of diabetes 14.5 +/- 0.8 years, insulin dose 63 +/- 2 units/day). We used the same examination method and criteria for assessment of LJM as used by us in an earlier study in 1981-1982.

RESULTS

The prevalence of LJM has fallen from 43 to 23% between the 1980s and 2002 (P < 0.0001). The relative risk for LJM in 2002 compared with the 1981-1982 cohort was 0.53 (0.40 < RR < 0.72, P < 0.0001). The prevalence of LJM was increased with longer duration of diabetes (<10 years, 13%; 10-20 years, 19%; 20-29 years, 30%; >30 years, 65%; P < 0.001). The relative risk for those with a mean HbA(1c) <7% in 2002 was 0.3 (0.1 < RR < 1.2, P = 0.05) when compared with those with mean HbA(1c) >7%.

CONCLUSIONS

The present study confirms the hypothesis that the prevalence of LJM is lower than 20 years ago and that improved standards of glycemic control and diabetes care may have contributed to this occurrence. Joint limitation in type 1 diabetes is strongly associated with duration of diabetes. The presence of LJM remains a common and important clinical marker for subsequent microvascular disease and can be a useful clinical tool for identification of patients at increased risk.

Changes in frequency and severity of limited joint mobility in children with type 1 diabetes mellitus between 1976-78 and 1998

OBJECTIVE

Limited joint mobility (LJM), the earliest clinically apparent long-term complication of type 1 diabetes mellitus, is a risk indicator for microvascular complications, and its appearance is primarily affected by long-term metabolic control. We hypothesized that the prevalence of LJM had decreased during the past 20 years.

STUDY DESIGN

We examined 312 subjects with type 1 diabetes mellitus, aged 7 to 18 years, using the same examination method and criteria as in studies of 515 subjects in this age group carried out between 1976 and 1978 for whom primary data were available, including age, duration of diabetes, and LJM stage. Statistical analyses included exact chi(2) tests, independent sample t tests, and unconditional logistic regression.

RESULTS

There was a >4-fold reduction in frequency of LJM between 1976-78 and 1998 (31% vs 7%, P <.001), with a decrease in the proportion having moderate or severe LJM (35% vs 9%, P =.025).

CONCLUSIONS

These findings confirm the hypothesis that the prevalence of LJM has decreased, most likely the result of improved blood glucose control during the past 2 decades.

Prevalence of microvascular and neurologic abnormalities in a population of diabetic children

One hundred and twenty-nine (87%) of a total county population of 150 eligible diabetic children together with 144 age- and sex-matched control children participated in a longitudinal, epidemiological study of the evolution of diabetic microvascular disease. At enrollment the median (range) age of the diabetic children was 12.5 (3.7-16.8) years with a median diabetes duration of 2.9 (0.1-13.4) years and a median HbAl of 11.1 (6.8-17.9)%. Two sets of measurements were made over a period of 18 months for all indices of microvascular disease, while autonomic function was studied on one occasion. Urinary albumin excretion in diabetic children was assessed from all voidings during two timed 48-h urine collections and was expressed as urinary albumin/creatinine ratios (ACR). Blood pressure (BP) was measured using a random zero sphygmomanometer. Autonomic function was assessed by pupillary adaptation in darkness, using a portable Polaroid pupillometer, and by heart rate (HR) variation recorded by dedicated computer. Vibration sensation thresholds (VST) (as indices of peripheral neuropathy) were recorded using a Biothesiometer. Limited joint mobility (LJM) was assessed by the "prayer sign". Five (3.9%) diabetic children presented raised mean ACR in more than two of four 24-h urine collections. Fourteen (10.8%) diabetic children were identified as having persistently raised BP during both study periods. Impaired HR response in one HR test was observed in 20 (15.5%) diabetic children, while ten (7.7%) diabetic children demonstrated abnormalities in two or more HR tests. Reduced pupillary adaptation in darkness was found in eight (7.9%) diabetic children. Persistent vibration sensation impairment (VST) in lower limbs was detected in eight (6.2%) diabetic children, while LJM was present in 12 (9.3%) diabetic children. Eight of the 129 diabetic children (6.2%) were found to have abnormality in two and one in three indices of microvascular and autonomic function. Six of nine children had coexistence of impaired autonomic neuropathy and nephropathy. These nine children were diagnosed at a younger age than the rest of the diabetic population (5.1 vs 8.0 yr, p=0.002). Four of nine were aged >11 yr and five of nine had had diabetes for >5 yr. Thus, a constellation of microvascular and neurological abnormalities were demonstrable in a small proportion of diabetic children, who were younger than the rest of the population at the time of onset of their disease. Longitudinal study of this population will demonstrate the clinical significance of these findings.

Long-term glycemic control influences the onset of limited joint mobility in type 1 diabetes

BACKGROUND

Limited joint mobility (LJM) in childhood insulin-dependent (type 1) diabetes is associated with a substantially increased risk of microvascular complications. Cross-sectional studies have not demonstrated a relationship between LJM and metabolic control. This study was designed to determine whether glycemic control, as measured by glycohemoglobin (hgbA1C) levels from the onset of diabetes, is associated with the occurrence of LJM.

METHOD

Probands (n = 18) had hgbA1C values and recorded observation of joint function from soon after onset of their diabetes. Controls (n = 40) were matched to probands for gender and age at diagnosis and had follow-up beyond the age at which the proband was found to have LJM.

RESULTS

The odds ratio for occurrence of LJM for the mean hgbA1C from diabetes onset was 1.46, 95% confidence limits 1.07 to 2.00. Thus, for every unit increase in average hgbA1C, there was approximately a 46% increase in the risk of LJM. When hgbA1C was dichotomized, the OR for hgbA1C of more than 8% was 2.55, and the OR was 4.54 if the hgbA1C was greater than 12%. Age at diagnosis and duration of diabetes were not independent prognostic factors for LJM.

CONCLUSION

Glycemic control from onset of diabetes is strongly associated with occurrence of LJM.

Limited joint mobility in non-insulin-dependent diabetic (NIDDM) patients: correlation to control of diabetes, atherosclerotic vascular disease, and other diabetic complications

This study examined the association between limited joint mobility (LJM) and diabetic control, atherosclerotic vascular disease and other diabetic complications in non-insulin-dependent diabetic (NIDDM) patients. LJM was studied in 139 [age (mean +/- SD) 61.3 +/- 12.3 years] NIDDM patients. Limitation of several joints was examined with a goniometer and LJM was classified by the Rosenbloom method. The NIDDM patients were examined for the following diseases: history of myocardial infarction, coronary heart, cerebrovascular and peripheral vascular diseases. The diabetic complications, background and proliferative retinopathy, nephropathy, and neuropathy, were also assessed. The metabolic control of the diabetes was evaluated by the average glycosylated hemoglobin Alc (GHbA kappa) concentration and lipid values were also measured. Mean levels of GHbAlc were 8.9 vs. 8.2% (p < 0.05) in NIDDM patients with and without LJM. NIDDM patients with LJM had a 3.1- (95% confidence interval, 1.2-7.7) and a 4.0-fold risk (95% confidence interval, 1.2-13.0) for coronary heart and cerebrovascular disease respectively, when the confounding effects of age, duration of diabetes and control of diabetes were controlled using stepwise logistic regression analysis. Patients with LJM had a 9.3- (95% confidence interval, 1.1-79.0) and a 3.3-fold risk (95% confidence interval, 1.0-10.5) of proliferative retinopathy and nephropathy respectively, when the confounding effects of age and duration of diabetes were controlled, but the correlation disappeared when control of diabetes was included in the model. In conclusion, the presence of LJM is associated with the control of diabetes and with the presence of coronary heart and cerebrovascular diseases in NIDDM patients.

Connective tissue and joint disease in diabetes mellitus

Connective tissue is ubiquitous and subject to alterations that result in changes in the extracellular matrix of vessels and tissues leading to the long-term complications of diabetes. This article reviews only those abnormalities of interstitial connective tissue involving skeleton, joints, skin, and periarticular tissues. Abnormalities in the skin and periarticular tissues result in syndromes limiting joint movement, including limited joint mobility, Dupuytren disease, flexor tenosynovitis, carpal tunnel syndrome, stiff-hand syndrome, and shoulder-hand reflex dystrophy. Of these, only limited joint mobility and stiff-hand syndrome occur exclusively in patients with diabetes. In all of these conditions, advanced glycation end products are thought to form as a result of nonenzymatic reaction of glucose with proteins, causing stiffening.

Risk factors for expression and progression of limited joint mobility in insulin-dependent childhood diabetes

We studied the prevalence of limited joint mobility (LJM) in 100 diabetic children and 100 non-diabetic controls. Our objective was to find possible predictors for the expression and progression of LJM and to evaluate the relationship between LJM and other long-term complications of insulin-dependent diabetes mellitus. LJM was present in 36% of diabetic patients aged 2-20 years. It was significantly related to duration of disease and longitudinal glycated haemoglobin (HbA1c) concentrations, pubertal stage, number of ketoacidosis and skin changes. Fourteen patients had peripheral neuropathy, 16 had microalbuminuria, 8 had nephropathy, and 7 had retinopathy. After matching for duration of disease, HbA1c concentrations and pubertal stage, a comparison of the complication rates was made. All long-term complications were significantly associated with LJM. Longer duration of disease and higher mean longitudinal glycated haemoglobin level are independent predictors for expression of LJM. Thus, improvement of metabolic control in diabetic patients before puberty may diminish the expression and progression of LJM.

Final adult height and its relationship to blood glucose control and microvascular complications in IDDM

The effect of longitudinal blood glucose control on final adult height was evaluated in 181 subjects (94 women and 87 men) with IDDM. Diabetes onset was at a median age of 6.9 years with an interquartile range of 4.7 years. Longitudinal glycated haemoglobin values were determined over a mean period of 6.6 +/- 2.6 years during their growth phase. Serial eye and joint examinations and urinary albumin excretion rates were performed with final assessment being carried out at a mean age of 21.1 +/- 3.0 years. The mean adult height standard deviation score of the whole group was -0.22 +/- 1.15 and was reduced compared to the mean height of the general population and to the mean height of the subjects' parents and siblings. There was an inverse correlation with mean longitudinal glycated haemoglobin and final adult height (p < 0.01). There was also an inverse relationship between adult height and the severity of eye, kidney, and joint complications, but when controlled by glycated haemoglobin, this relationship only remained significant for eye complications. Final adult height is reduced in subjects with early onset IDDM who remain in poor blood glucose control during their growth period.

Limited joint mobility and lipodystrophy in children and adolescents with insulin-dependent diabetes mellitus

One hundred forty-eight children, aged 11.9 +/- 3.7 years, who had insulin-dependent diabetes mellitus (IDDM) for 4.5 +/- 3.7 years and glycosylated Hb values (HbA1) of 10.5% +/- 4.5%, were examined for limited joint mobility (LJM) and lipodystrophy. In all diabetics, human biosynthetic insulin was used. Six hundred forty-eight pupils, aged 11.8 +/- 2.5 years, served as controls. LJM was found in 28.4% of the diabetics and in 7.5% of the controls (p < 0.001). The presence and severity of LJM was positively correlated with the duration of diabetes and negatively with height. There was no correlation between the presence of LJM and sex, chronological age, age of diabetes onset, HbA1 values, or retinopathy. Lipodystrophy at insulin injection sites was found in 37.1% of the diabetics. Hypertrophic lesions predominated. Our findings and those of the literature lead to the following conclusions: the prevalence of LJM in IDDM subjects of comparable age using Rosenbloom's criteria is almost uniform in all published studies (28%); the correlation, however, of prevalence and severity to different parameters presents discrepancies which cannot be interpreted at present. Human biosynthetic insulin does not protect from lipodystrophy and alterations of insulin injections still remain the only currently available preventive and therapeutic measure.

Incidence of microvascular complications in type 1 diabetic subjects with limited joint mobility: a 10-year prospective study

Previous cross-sectional studies have shown a significant correlation between limited joint mobility (LJM) and the microvascular complications of Type 1 diabetes, but whether LJM precedes and, therefore, may be regarded as an early marker for complications is unknown. Twenty-two Type 1 diabetic patients (10 male/12 female; diabetes duration at follow-up 20.1 +/- 1.3 (SEM) years) with LJM, and 22 subjects matched for age, sex, and duration of diabetes, without LJM were observed over a 10-year period. Both groups were free of retinopathy and negative for 'dipstick' proteinuria at baseline. After 10 years, of 22 patients with LJM, 10 had developed background and 3 proliferative retinopathy compared with 9 and 1 control subjects, respectively. Microalbuminuria (20 < or = albumin excretion rate < 200 micrograms min-1) was present in 3 and macroalbuminuria (albumin excretion rate > or = 200 micrograms min-1) in 2 of LJM patients compared with 6 and 1 control subjects, respectively. Ankle and toe vibration perception thresholds, HbA1, mean HbA1 (a mean of serial HbA1 measurements obtained during the 10-year follow-up period), and arterial blood pressure did not differ between the two groups (p > 0.05). At 10-year review, 9 of the control subjects had developed LJM of whom 4 had retinopathy and 4 microalbuminuria. Thus, while LJM may be another 'chronic complication' of diabetes, its presence does not appear to predict those at increased risk of developing microvascular complications.

Factors influencing the onset and progression of diabetic retinopathy in subjects with insulin-dependent diabetes mellitus

BACKGROUND

The etiology of diabetic retinopathy is poorly understood. In the current study, factor associated with the onset and the progression or regression of retinopathy are evaluated.

METHODS

Two hundred seventy-seven subjects with insulin-dependent (type I) diabetes mellitus (IDDM) were evaluated longitudinally for retinal changes over a mean of 2.7 years. The multistate Markov model was used to analyze the influences of the duration of diabetes, a family history of hypertension, age, sex, cigarette smoking, systolic blood pressure, diastolic blood pressure, cholesterol levels, and longitudinal glycohemoglobin (GHb) values on the development and the progression or regression of retinopathy.

RESULTS

Univariate analysis confirmed that four factors were significantly associated with the etiology and the progression or regression of diabetic retinopathy: age, duration of diabetes, mean longitudinal GHb levels (all at P < 0.01), and diastolic blood pressure (P < 0.04). However, age was no longer significant when controlled by duration of diabetes. Cigarette smoking was only associated significantly with background retinopathy (stages 2 and 3). Systolic blood pressure, sex, a family history of hypertension, and cholesterol levels were not significantly associated with retinopathy.

CONCLUSIONS

The onset of diabetic retinopathy is associated with the duration of diabetes, mean longitudinal GHb levels, smoking, and diastolic blood pressure. A longer duration of diabetes, higher GHb values, and higher diastolic blood pressure levels are associated with an increased risk of progression and a decreased chance of regression of diabetic retinopathy.