PubMed Health⌕ Search

Biomedical subjects

M C Riddle

Publications and source records attributed to M C Riddle.

At least 19 recordsLinked to original sources
PubMed2001

A randomized trial of rosiglitazone therapy in patients with inadequately controlled insulin-treated type 2 diabetes.

OBJECTIVE: To determine the efficacy and safety of rosiglitazone (RSG) when added to insulin in the treatment of type 2 diabetic patients who are inadequately controlled on insulin monotherapy. RESEARCH DESIGN AND METHODS: After 8 weeks of insulin standardization and placebo (PBO) run-in, 319 type 2 diabetic patients with mean baseline HbA(1c) > or = 7.5% (8.9 +/- 1.1 to 9.1 +/- 1.3) on twice-daily insulin therapy (total daily dose > or = 30 U) were randomized to 26 weeks of additional treatment with RSG (4 or 8 mg daily) or PBO. Insulin dose could be down- titrated only for safety reasons. The primary end point was reduction of HbA(1c) from baseline. RESULTS: RSG 4 and 8 mg daily significantly improved glycemic control, which was unchanged on PBO. By intent-to-treat analysis, treatment with RSG 8 mg plus insulin resulted in a mean reduction from baseline in HbA(1c) of 1.2% (P < 0.0001), despite a 12% mean reduction of insulin dosage. Over 50% of subjects treated daily with RSG 8 mg plus insulin had a reduction of HbA(1c) > or = 1.0%. Neither total:HDL cholesterol nor LDL:HDL cholesterol ratios significantly changed with RSG treatment. Serious adverse events did not differ among groups. CONCLUSIONS: The addition of RSG to insulin treatment results in significant improvement in glycemic control and is generally well tolerated.

Adult↗
PubMed1999

Oral pharmacologic management of type 2 diabetes.

Epidemiologic and interventional studies have led to lower treatment targets for type 2 diabetes (formerly known as non-insulin-dependent diabetes), including a glycosylated hemoglobin level of 7 percent or less and a before-meal blood glucose level of 80 to 120 mg per dL (4.4 to 6.7 mmol per L). New oral medications make these targets easier to achieve, especially in patients with recently diagnosed diabetes. Acarbose, metformin, miglitol, pioglitazone, rosiglitazone and troglitazone help the patient's own insulin control glucose levels and allow early treatment with little risk of hypoglycemia. Two new long-acting sulfonylureas (glimepiride and extended-release glipizide) and a short-acting sulfonylurea-like agent (repaglinide) simply and reliably augment the patient's insulin supply. Combinations of agents have additive therapeutic effects and can restore glucose control when a single agent is no longer successful. Oral therapy for early type 2 diabetes can be relatively inexpensive, and evidence of its cost-effectiveness is accumulating.

1-Deoxynojirimycin↗
PubMed1998

Beginning insulin treatment of obese patients with evening 70/30 insulin plus glimepiride versus insulin alone. Glimepiride Combination Group.

OBJECTIVE: This study tested a simple algorithm for beginning insulin for obese patients with type 2 diabetes after sulfonylurea failure, comparing suppertime 70/30 insulin plus continued glimepiride with insulin alone. RESEARCH DESIGN AND METHODS: This was a multicenter ambulatory randomized double-masked parallel comparison. There were 208 subjects with secondary failure to sulfonylureas who took glimepiride titrated to 8 mg b.i.d. for 8 weeks; 145 subjects with fasting plasma glucose (FPG) 180-300 mg/dl (10-16.7 mmol/l) on this treatment were randomized to placebo plus insulin (PI) or glimepiride plus insulin (GI) for 24 weeks. A dosage of 70/30 insulin before supper was titrated, seeking fasting capillary blood glucose (FBG) 120 mg/dl (6.7 mmol/l), equivalent to FPG 140 mg/dl (7.8 mmol/l). Outcome measures included FPG, HbA1c, insulin dosage, weight, serum insulin and lipids, and adverse events. RESULTS: FPG and HbA1c were equivalent at baseline: 261 vs. 250 mg/dl (14.5 vs. 13.9 mmol/l), and 9.9 vs. 9.7%. At 24 weeks, the FPG target was achieved in both groups (136 vs. 138 mg/dl, 7.6 vs. 7.6 mmol/l), and HbA1c values were equal (7.7 vs. 7.6%). However, with GI, control improved faster and fewer subjects dropped out (3 vs. 15%, P < 0.01), and less insulin was needed (49 vs. 78 U/d, P < 0.001). The outcomes were alike in other respects. No subject had severe hypoglycemia. CONCLUSIONS: Injection of 70/30 insulin before supper safely restored glycemic control of type 2 diabetes not controlled by glimepiride alone. Control was restored more rapidly and with less injected insulin when glimepiride was continued.

Aged↗
PubMed1997

Long-term effects and costs of brief behavioural dietary intervention for patients with diabetes delivered from the medical office.

This study evaluated the 12-month follow-up results and costs of a personalized, medical office-based intervention focused on behavioral issues related to dietary self-management. Two hundred and six adults having diabetes attending an internal medicine outpatient clinic visit were randomized to either Usual Care or to Brief Intervention. The single session intervention involved touchscreen computer-assisted assessment that provided immediate feedback on key barriers to dietary self-management, goal setting and problem-solving counselling. Follow-up components included phone calls and videotape intervention relevant to each participant. Brief Intervention produced significantly greater improvement than Usual Care on multiple measures of change in dietary behaviour (e.g., covariate adjusted difference of 2.2% of calories from fat; p = 0.023) and on serum cholesterol levels (covariate adjusted difference of 15 mg/dl; p = 0.002) at 12-month follow-up. There were also significant differences favouring intervention on patient satisfaction (p < 0.02) but not on HbA1c levels. The costs of intervention ($137 per patient) were modest relative to many commonly used practices.

Computer-Assisted Instruction↗
PubMed1997

Tactics for type II diabetes.

Type II diabetes is a prototype of chronic diseases. Given its human and economic importance, it deserves a comprehensive strategy for management; this should include a public health phase, a primary medical management phase, and a complex management phase. Public health tactics include finding susceptible persons, teaching preventive habits, and screening for early diagnosis. Primary management tactics include enhancing life-style efforts, prescribing single and combined drug regimens as directed by algorithms, and objectively testing short-term outcomes. Complex management deals with patients with diabetic complications or poor glucose control despite algorithmic tactics, who therefore need individualized treatments.

Administration, Oral↗
PubMed1997

Glipizide-GITS does not increase the hypoglycemic effect of mild exercise during fasting in NIDDM.

OBJECTIVE: This study compared the effect of mild exercise while fasting on plasma glucose concentrations in subjects with NIDDM treated with extended-release glipizide and subjects not taking an oral hypoglycemic agent. RESEARCH DESIGN AND METHODS: Twenty-five moderately obese subjects with NIDDM were randomized to treatment with extended-release glipizide or placebo. After 9 weeks of treatment, they fasted overnight, took their study drug, omitted breakfast, and exercised on a treadmill for 90 min. Glucose, insulin, and C-peptide concentrations were measured before, during, and after exercise. RESULTS: On the fasting-exercise day, fasting glucose concentrations were lower (153 vs. 241 mg/dl, P < 0.01) and insulin and C-peptide concentrations higher in the extended-release glipizide group. The decrement of glucose from the fasting baseline was modest and equivalent in the two groups: 17 vs. 21 mg/dl at the end of exercise and 28 vs. 27 mg/dl after 2 h of recovery. No subject had hypoglycemic symptoms. CONCLUSIONS: Chronic use of extended-release glipizide does not enhance the hypoglycemic effect of fasting plus mild exercise for people with NIDDM. Routine lifestyle treatments for NIDDM may be continued during ongoing use of this agent.

Adult↗
PubMed1996

Combined therapy with a sulfonylurea plus evening insulin: safe, reliable, and becoming routine.

Whether a sulfonylurea may be used together with insulin for treating NIDDM has been controversial. One view, based on older studies, has been that the additional benefit is too small or the level of glucose control achieved usually too poor to recommend this method. More recent studies of a more specific way of combining a sulfonylurea with insulin are more supportive. When a single injection of insulin taken in the evening is added to a sulfonylurea at the time of secondary failure of the sulfonylurea alone, glycemic control is quite simply and consistently restored to acceptable levels. At this time in the natural history of NIDDM, evening insulin combined therapy is more effective than a single injection of insulin alone, and just as effective as a more complex multiple-injection regimen without an oral agent. A recent multicenter trial of a new sulfonylurea, glimepiride, in combination with a single injection of 70/30 insulin before dinner has confirmed that this approach is safe and more consistently effective than insulin alone for obese patients beginning insulin in a setting resembling clinical practice. The available evidence suggests this form of combined therapy is suitable for routine use.

Diabetes Mellitus, Type 2↗
PubMed1994

Renal 11 beta-hydroxysteroid dehydrogenase activity is enhanced by ramipril and captopril.

Changes of renal 11 beta-hydroxysteroid dehydrogenase activity may contribute to variations of sodium excretion by modulating inactivation of cortisol or corticosterone and thus their access to mineralocorticoid receptors. Angiotensin-converting enzyme inhibitors enhance sodium excretion but by mechanisms still incompletely understood. To test the hypothesis that the angiotensin-converting enzyme inhibitors ramipril and captopril act in part by enhancing renal 11 beta-hydroxysteroid dehydrogenase activity, the effects of these agents in slices of rat renal outer medulla were examined. Conversion of 3H-corticosterone to 3H-11-dehydrocorticosterone was 58% greater in tissue from fasted rats than from fed rats (mean +/- SE 2467 +/- 146 vs. 1584 +/- 102 pmol/mg protein.h, P < 0.01). Incubation of tissue from fed rats with physiological concentrations of ramiprilat, the active form of ramipril, enhanced activity (1497 +/- 76) to fasted levels (2323 +/- 120, P < 0.02). Captopril had a similar in vitro effect (1557 +/- 92 to 2109 +/- 116, P < 0.01). Ramipril given in vivo to fed rats also increased activity to fasted levels (1716 +/- 101 to 2737 +/- 396, P < 0.05). Angiotensin II incubated with renal tissue from fasted rats suppressed activity to fed levels, but this effect was prevented by the presence of ramiprilat. Both ramipril and captopril enhance renal 11 beta-hydroxysteroid dehydrogenase activity, and this effect is only partly explained by limitation of endogenous angiotensin II production.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1993

Acute reduction of renal 11 beta-hydroxysteroid dehydrogenase activity by several antinatriuretic stimuli.

The 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) activity of the kidney prevents access of cortisol or corticosterone to the renal mineralocorticoid receptor. Reduction of 11 beta-HSD activity by nutritional, hormonal, or pharmacologic factors might enhance the mineralocorticoid effect of these corticosteroids, thus causing sodium retention. To test this concept, we studied the effect on 11 beta-HSD activity of several antinatriuretic factors given orally to rats or exposed in vitro to rat renal tissue. Renal 11 beta-HSD activity was higher in fasted than fed rats (P < .05). Glucose, ethanol, and Toradol (Syntex Laboratories, Palo Alto, CA) given orally to fasted rats all reduced renal 11 beta-HSD activity by 20% to 40% (P < .05-.005) to levels similar to those observed in fed animals. Incubation of renal tissue from fasted rats with physiologic concentrations of insulin, ethanol, and Toradol also reduced 11 beta-HSD activity by 20% to 40% (P < .05-.01). These findings are consistent with the hypothesis that the antinatriuretic actions of these stimuli are due in part to alteration of renal 11 beta-HSD leading to greater mineralocorticoid effects in kidney.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1992

Combining insulin and sulfonylurea. A therapeutic option for type II diabetes.

Non-insulin-dependent (type II) diabetes mellitus is a progressive disease that requires sequential therapy to achieve optimal control. When diet and sulfonylurea fail to maintain glycemic control, the addition of a single daily injection of insulin may be indicated. The best candidates for this combined therapy are patients with typical adult-onset disease that has been present less than 10 to 15 years.

Diabetes Mellitus, Type 2↗
PubMed1992

A model for the apparent decrease in optical transmittance of the diabetic eye.

This paper compares observed changes of ocular transmittance at short and long wavelengths in diabetic patients with values predicted by a model based on the Rayleigh light scattering properties of albumin. Selective chromatic adaptation was used to obtain critical flicker fusion (CFF) frequency thresholds from 21 subjects and 18 patients with insulin-dependent diabetes. The Ferry-Porter characteristic of each color-sensitive mechanism of each patient was compared to age-specific control values. For those eyes without an indication of neural injury, changes in optical density associated with the red- and blue-sensitive mechanisms were calculated and adjusted to reflect accelerated yellowing of the lens produced by increased duration of diabetes. The range of concentration of glycosylated albumin required to fit the model to the adjusted short-wavelength changes in optical density was determined and used to calculate the theoretical long-wavelength changes in optical density. The experimentally derived long-wavelength changes in optical density fell within the 95% confidence level of the values described by the model. These results support the premise that the apparent decrease in optical transmittance observed in patients with diabetes mellitus is caused by light scattering produced by dilute increase of plasma proteins within the retina.

Adaptation, Ocular↗