Biomedical subjects

Daniel J Cox

Publications and source records attributed to Daniel J Cox.

30 records · Page 2Linked to original sources

PubMed2003

Algorithmic evaluation of metabolic control and risk of severe hypoglycemia in type 1 and type 2 diabetes using self-monitoring blood glucose data.

The optimization of metabolic control in Type 1 and Type 2 diabetes mellitus (T1DM and T2DM, respectively) [i.e., the maintenance of near-normal hemoglobin A(1c) (HbA(1c)) without increasing the risk of hypoglycemia] could be enhanced by analysis of self-monitoring blood glucose (SMBG) data assessing complementary processes: exposure to hyperglycemia and hypoglycemia. We present algorithms that simultaneously estimate HbA(1)c and risk for significant hypoglycemia using 45-60 days of SMBG. The algorithms were developed using a primary data for 96 subjects with T1DM (n = 48) and T2DM, and were validated in an external data for 520 subjects with T1DM (n = 231) and T2DM. All subjects were on insulin. In the primary (external) data the estimation of HbA(1c) had absolute error of 0.5 (0.7) units of HbA(1c) and percent error of 6.8% (8.1%); 96% (96%) of all estimates were within 20% from reference HbA(1c). The SMBG-estimated value of HbA(1c) was closer to current reference HbA(1c) than a reference HbA(1c) value taken only 2-3 months ago. The results in T1DM and T2DM were similar. Linear model predicted future significant hypoglycemia (R(2) = 62%, p < 0.0001). The leading predictor was a previously introduced Low Blood Glucose Index, which alone had R(2) = 55%. Probability model assessed accurately the odds for future moderate/severe hypoglycemia (coefficients of determination 92%/94%). Four risk categories were identified; within moderate- and high-risk category, there was no difference between T1DM and T2DM in the occurrence of prospective significant hypoglycemia. SMBG data allow for accurate estimation of the two most important markers of metabolic control in T1DM and T2DM - HbA(1c) and risk for hypoglycemia.

Adult↗

PubMed2003

Assessment of behavioral mechanisms maintaining encopresis: Virginia Encopresis-Constipation Apperception Test.

OBJECTIVE: To develop and test a scale for parent and child, evaluating theoretical and clinical parameters relevant to children with encopresis. Encopretic children were hypothesized to have more bowel-specific, but not more generic, psychological problems, as compared with nonsymptomatic control children. In addition, mothers were also believed to be more discerning than children. METHODS: The Virginia Encopresis-Constipation Apperception Test (VECAT) consists of 9 pairs of bowel-specific and 9 parallel generic drawings. Respondents selected the picture in each pair that best described them/their child. It was administered to encopretic children (N = 87), nonsymptomatic siblings (N = 27), and nonsymptomatic nonsiblings (N = 35). The mothers of all the participants also completed the VECAT. Encopretic children were retested 6 and 12 months posttreatment with Enhanced Toilet Training. RESULTS: The VECAT demonstrated good test-retest reliability and internal consistency. Encopretic children and their mothers reported more bowel-specific, but not more generic, problems. Bowel-specific scores improved significantly posttreatment only for those patients who demonstrated significant symptom improvement. Mothers were significantly more discerning than children. CONCLUSION: The VECAT is a reliable, valid, discriminating, and sensitive test. Bowel-specific problems appear to best differentiate children with and without encopresis.

Child↗

PubMed2003

Diabetes and driving mishaps: frequency and correlations from a multinational survey.

OBJECTIVE: The intensive treatment of diabetes to achieve strict glycemic control is a common clinical goal, but it is associated with an increased incidence of hypoglycemia. Becoming hypoglycemic while driving is a hazardous condition and may lead to a greater incidence of driving mishaps. This study investigated whether diabetes is associated with increased risk of driving mishaps and correlates of such a relationship. RESEARCH DESIGN AND METHODS: During routine visits to diabetes specialty clinics in seven U.S. and four European cities, consecutive adults with type 1 diabetes, type 2 diabetes, and nondiabetic spouse control subjects (n = 341, 332, and 363, respectively) completed an anonymous questionnaire concerning diabetes and driving. RESULTS: Type 1 diabetic drivers reported significantly more crashes, moving violations, episodes of hypoglycemic stupor, required assistance, and mild hypoglycemia while driving as compared with type 2 diabetic drivers or spouse control subjects (P < 0.01-0.001). Type 2 diabetic drivers had driving mishap rates similar to nondiabetic spouses, and the use of insulin or oral agents for treatment had no effect on the occurrence of driving mishaps. Crashes among type 1 diabetic drivers were associated with more frequent episodes of hypoglycemic stupor while driving, less frequent blood glucose monitoring before driving, and the use of insulin injection therapy as compared with pump therapy. One-half of the type 1 diabetic drivers and three-quarters of the type 2 diabetic drivers had never discussed hypoglycemia and driving with their physicians. CONCLUSIONS: Type 1 diabetic drivers are at increased risk for driving mishaps, but type 2 diabetic drivers, even on insulin, appear not to be at a higher risk than nondiabetic individuals. Clinical and treatment factors appear to increase risk, e.g., more frequent hypoglycemia while driving, method of insulin delivery, and infrequent self-testing before driving. Physicians are encouraged to talk to their type 1 diabetic patients about hypoglycemia and driving.

Accidents, Traffic↗

PubMed2002

Diabetes and behavioral medicine: the second decade.

Diabetes management depends almost entirely on behavioral self-regulation. Behavioral scientists have continued a collaboration with other health systems researchers to develop a holistic approach to this disease. The authors summarized the literature in 4 major areas: self-management of diabetes, psychosocial adjustment and quality of life, neuropsychological impact, and psychobehavioral intervention development. Progress made in each of these areas over the past decade is highlighted, as are important issues that have not yet received sufficient scientific attention. Emerging areas likely to become central in behavioral research, such as diabetes prevention, are introduced. The future of behavioral medicine in diabetes is also discussed, including topics such as the changing role of psychologists in diabetes care, the urgent need for more and better intervention research, the growing importance of incorporating a health system-public health perspective, and obstacles to the integration of psychobehavioral approaches into routine health care delivery.

Behavioral Medicine↗

PubMed2002

Methods for quantifying self-monitoring blood glucose profiles exemplified by an examination of blood glucose patterns in patients with type 1 and type 2 diabetes.

The maintenance of glycemic control in patients with type 1 or type 2 diabetes mellitus (T1DM and T2DM, respectively) is commonly assisted by devices for self-monitoring of blood glucose (SMBG) that store multiple BG determinations. However, besides average BG, no other SMBG characteristics are routinely computed. We describe several SMBG-based measures that quantify the extent and rate of patients' BG excursions into hypoglycemia and hyperglycemia and can be used as markers for patients' vulnerability to hypoglycemia and BG irregularity. These markers are applied to analyze data from patients with T1DM (n = 277) and T2DM (n = 323), all of whom used insulin. T1DM and T2DM patients were matched by HbA(1c), gender, and number of SMBG readings/day. On average, 230 SMBG readings and three HbA(1c) assays were collected for each subject over 3 months. Compared with T2DM, patients with T1DM diabetes had (1) more extreme low and high BGs, (2) greater risk for severe hypoglycemia as quantified by the Low BG Index, (3) faster descent into hypoglycemia as quantified by the risk rate of change/hour, and (4) greater BG irregularity as computed by BG rate of change/hour and BG SD (all p levels < 0.0001). SMBG data allow for computing and frequent updating of various idiosyncratic diabetes characteristics and risk factors. The use of such computations may assist in optimizing patients' glycemic control.

Adult↗

PubMed2002

Treatment of childhood encopresis: a randomized trial comparing three treatment protocols.

OBJECTIVES: To compare short- and long-term effectiveness of three additive treatment protocols in children experiencing chronic encopresis. METHODS: Children, 6 to 15 years of age, who experienced at least weekly fecal soiling for 6 months or longer were eligible for the study. Children were randomly assigned to a group that received intensive medical therapy (IMT), a group that received intensive medical therapy plus a behavior management program called enhanced toilet training (ETT), or a group that received intensive medical therapy with enhanced toilet training and external anal sphincter electromyographic biofeedback (BF). Data concerning toileting habits were collected for 14 consecutive days before an initial visit, and at 3, 6, and 12 months after initiation of therapy. All data were collected using a computerized voice-mail system that telephoned the families each day. At 12 months, children were classified as significantly improved (reduction in soiling, P < 0.001) or cured ( 0.90, P < 0.001 in each case). Response to treatment during the first 2 weeks of therapy was highly predictive of outcome at 3, 6, and 12 months (P < 0.0001). Children in the ETT group used less laxative medication (P < 0.04) and required fewer treatment contacts (P = 0.08) than children in the IMM group. All three treatments resulted in significant increases in daily bowel movements passed in the toilet and self-initiated toileting, and resulted in decreases in average daily soiling at 3, 6, and 12 months (P < 0.05). CONCLUSIONS: Enhanced toilet training is somewhat more effective in treating childhood encopresis than either intensive medical therapy or anal sphincter biofeedback therapy. Although similar total cure rates at 1 year can be expected with these three forms of therapy, enhanced toilet training results in statistically significant decreases in the daily frequency of soiling for the greatest number of children.

Adolescent↗

PubMed1990

Effect of hyperglycemia on pain threshold in alloxan-diabetic rats.

Insulin-dependent diabetes mellitus (IDDM) is associated with several complications, including painful diabetic neuropathy. Both animal and human investigations suggest an altered pain response in IDDM. Furthermore, it has been suggested that glucose may be an important mediating factor in these painful symptoms. In the present study, pain threshold was assessed via tail flick latency in alloxan-diabetic and control rats. In addition, tail flick latency was determined under conditions of both hyperglycemia and euglycemia in diabetic rats. Conditions of hyperglycemia resulted in a significant decrease in the tail flick latency of alloxan-diabetic rats. In contrast, tail flick latency was significantly increased in diabetic rats following normalization of blood glucose levels. It is concluded that elevated blood glucose levels contribute to a decrease in pain threshold in alloxan-diabetic rats.

Animals↗

PubMedDate not supplied

The metabolic demands of driving for drivers with type 1 diabetes mellitus.

BACKGROUND: The active cognitive-motor demands of driving may have a significant metabolic demand that could contribute to the development of hypoglycemia. Conversely, symptoms caused by the stress of driving may be confused with hypoglycemia and lead to false alarms. This study examined the metabolic demand and the physiological stress of driving on type 1 diabetes mellitus (T1DM) drivers. METHODS: Forty-three T1DM drivers were placed on a constant insulin infusion/variable dextrose infusion to maintain euglycemia for 30 min while either watching a driving video or actually driving a simulator, in a counterbalanced crossover design. Dextrose infusion, heart rate, epinephrine, and subjective symptom ratings were measured every 5 min. Additionally, subjects were monitored for self-treatment (drinking soda). RESULTS: While blood glucose (BG) levels were equivalent across both conditions, actual driving was associated with a higher dextrose infusion rate (p = 0.02), more autonomic symptoms (p < 0.05), increased heart rate (p < 0.001), a trend (p = 0.09) for greater epinephrine release, and more frequent hypoglycemic self-treatment (p < 0.001). CONCLUSIONS: Driving is a task with a significant metabolic demand, which may lower BG, and also that driving stress may be associated with symptoms similar to those of hypoglycemia. Physicians should discuss with their T1DM patients hypoglycemia and driving, and encourage measuring blood glucose before driving and during long drives.

Adult↗

PubMedDate not supplied

Psychological differences between children with and without chronic encopresis.

OBJECTIVE: To validate a theoretical model of encopresis in terms of psychological factors that differentiates children with and without chronic encopresis and to identify scales that demonstrate these differences. METHODS: Eighty-six children with encopresis were compared to 62 nonsymptomatic children on five psychometric instruments. Differences in the mean scores and the percentages of children falling beyond preselected clinical thresholds were compared across the patient-control groups. RESULTS: Children with encopresis were found to have more anxiety/depression symptoms, family environments with less expressiveness and poorer organization, more attention difficulties, greater social problems, more disruptive behavior, and poorer school performance (ps =.01 < or =.001 on 15/20 subscales). There were no differences in self-esteem. On those subscales where proportionately more encopretic children exceeded clinical thresholds, approximately 20% more of the encopretic children exceeded thresholds than control children. CONCLUSIONS: As a group, children with encopresis differ from children without encopresis on a variety of psychological parameters. However, only a minority of children with encopresis demonstrated clinically significant elevations in these parameters. Identification and treatment of such clinical issues may enhance treatment efficacy.

Adolescent↗

PubMedDate not supplied

Current status of mind-body interventions for vascular complications of diabetes.

Impaired peripheral blood flow causes complications, disabilities, expenses, and deaths among persons with diabetes mellitus. Many individuals suffer from lower-extremity pain, reduced functional status, and impaired quality of life. Current conventional treatments include lifestyle modification, exercise, medication, and surgery. However, these approaches are often impractical or insufficient. Thermal biofeedback, however, alone or in conjunction with other mind-body techniques, improves peripheral circulation, pain, neuropathy, ulcer healing, ambulatory activity, and quality of life. It is noninvasive, inexpensive, and consistent with community-based approaches to diabetes self-management. As an adjunct to the medical management of diabetes, thermal biofeedback may help ameliorate some of the vascular complications.

Biofeedback, Psychology↗

PubMedDate not supplied

Precipitants of constipation during early childhood.

BACKGROUND: Childhood constipation is a common problem, accounting for 3% of visits to pediatric clinics and 30% of visits to pediatric gastroenterologists. Estimates of the prevalence of childhood constipation vary from 0.3% to 28% with younger children being affected most often. We were unable to find any studies that specifically examine the causes of constipation in young children. Our objective of the study was to determine precipitants to constipation during early childhood. METHODS: Findings from 125 families visiting their primary care physician for the first time with a child aged between 2 and 7 years with the complaint of constipation were compared with findings from 95 children between 2 and 7 years without any history of constipation. Parents answered questions concerning family history, toilet training, and bowel habits. Parents of constipated children were asked to describe events that occurred during the 3 months before the onset of constipation and whether these events contributed to the child's constipation. RESULTS: The age and sex of children who did and did not suffer from constipation were comparable (P > .3). When compared with control children, constipated children were no more likely to have a parent (30% vs 40%, P = .14) or sibling (17% vs 14%, P = .54) with a history of constipation. Constipated children did not begin toilet training earlier than did control children (28 +/- 7 vs 27 +/- 6 months, P = .30). When compared with parents of control children, parents of constipated children reported more difficulties with toilet training (P < .001). Parents of constipated children indicated their children had more difficult and more painful defecation experiences than did parents of control children (P < .001), and constipated children were more likely to express worry about future painful defecation than were control children (P < .001). Parents of constipated children described a number of events that occurred before the onset of constipation; however, they did not consider many of the events important contributors to the constipation. Painful defecation was the event most often reported as causing the constipation. CONCLUSION: Painful defecation is the primary precipitant of constipation during early childhood. Parents should be counseled to be attentive to such experiences and taught to intervene quickly to lessen the risk that their child will develop persistent constipation or fecal soiling.

Child↗

PubMedDate not supplied

Controlled-release methylphenidate improves attention during on-road driving by adolescents with attention-deficit/hyperactivity disorder.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is associated with a 3- to 4-fold increase in both driving-related accidents and associated injuries. Methylphenidate (MPH) is the most commonly prescribed psychostimulant medication for ADHD. It has been demonstrated to improve performance on a driving simulator. This study investigated whether a once-daily, long-acting, osmotic, controlled-release MPH formulation improves the driving performance of ADHD adolescents while driving their own car on an actual road segment. METHODS: Twelve ADHD-diagnosed male adolescent drivers (mean age, 17.8 years) prescribed a standard dose of 1.0 mg/kg (if they were not already taking methylphenidate) of controlled-release MPH participated in this repeated-measures crossover study. On 2 separate occasions (off/on medication randomized), participants drove a standard 16-mile road course incorporating rural, highway, and urban streets. A rater, blind to medication conditions, sat in the back seat and rated impulsive (eg, "cutting off" another driver) and inattentive (eg, drove past designated turn) driving errors. RESULTS: Impulsive driving errors were observed to occur rarely under both medication and no medication conditions. Inattentive driving errors were more common and were significantly reduced while the subject was on medication (4.6 versus 7.8; P <.01). The improvement in driving performance (change in number of errors recorded) from first to second testing was positively correlated with medication dosage (r = 0.60; P <.01). CONCLUSIONS: Once-daily controlled-release MPH improves real-life driving performance of adolescent males diagnosed with ADHD. In particular, it significantly reduces driving errors arising from inattention.

Adolescent↗