Osmotic diuresis with SGLT2 inhibition: analysis of events related to volume reduction in dapagliflozin clinical trials.

OBJECTIVE: Dapagliflozin reduces hyperglycemia in type 2 diabetes mellitus (T2DM) and lowers blood pressure, at least in part, secondary to mild diuresis consequent to dapagliflozin-induced glucosuria. While blood-pressure lowering may contribute to cardiovascular risk reduction, dapagliflozin-induced diuresis may potentially contribute to adverse events (AEs) of volume reduction. The present analysis compared the frequency of AEs of volume reduction between dapagliflozin and placebo. METHODS: Pooled data were assessed from 13 placebo-controlled dapagliflozin clinical trials ≤24 weeks in patients with T2DM, overall, and in those at risk (aged ≥65y, estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m(2), or on antihypertensive therapy). Longer-term (≤104 weeks) data were available for 9 of these trials. RESULTS: The frequency of patients experiencing ≥1 AE of volume reduction over 24 weeks was low overall; 27/2360 (1.1%) with dapagliflozin 10 mg and 17/2295 (0.7%) with placebo; and slightly more frequent in patients ≥65 years (11/665 [1.7%] and 6/711 [0.8%], respectively) and in patients receiving loop diuretics (6/236 [2.5%] and 4/267 [1.5%], respectively). Over 104 weeks, AEs of volume reduction occurred in 38/2026 (1.9%) with dapagliflozin 10 mg and in 27/1956 (1.4%) with placebo; serious AEs of volume reduction in 4/2026 (0.2%) and 6/1956 (0.3%), respectively; and 2 patients in each group discontinued therapy due to these AEs. Dapagliflozin versus placebo incidence rate ratios did not suggest any meaningful increase in frequency of these AEs with dapagliflozin 10 mg, either overall or in those at risk. Although mean eGFR declined by 4.2 ml/min/1.73 m(2) within the first week of dapagliflozin therapy, thereafter eGFR gradually recovered to baseline levels by 104 weeks (mean change from baseline +0.02 mL/min/1.73 m(2); 95%CI: -0.9, 1.0). CONCLUSION: No meaningful increase in frequency of AEs of volume reduction occurred with dapagliflozin 10 mg in patients with T2DM, either overall, or in those at increased risk of these events. However, caution should nevertheless be exercised when prescribing dapagliflozin to elderly patients, those with reduced eGFR, and those receiving antihypertensive medication.

Dapagliflozin's Effects on Glycemia and Cardiovascular Risk Factors in High-Risk Patients With Type 2 Diabetes: A 24-Week, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study With a 28-Week Extension.

OBJECTIVE: To assess the efficacy and safety of dapagliflozin, a selective sodium-glucose cotransporter 2 inhibitor, compared with placebo in patients with type 2 diabetes (T2D), documented pre-existing cardiovascular disease (CVD), and a history of hypertension. RESEARCH DESIGN AND METHODS: Patients (N = 922) were randomized to receive 10 mg dapagliflozin or placebo in a double-blind trial for 24 weeks, followed by a 28-week extension period. In patients receiving insulin, the insulin dose was reduced by 25% at randomization. Patients were stratified by age, insulin use, and time from the most recent qualifying cardiovascular (CV) event. Co-primary end points were a change from baseline in hemoglobin A1c (HbA1c) and the proportion of patients achieving a combined reduction in HbA1c of ≥0.5% (5.5 mmol/mol), body weight (BW) of ≥3%, and systolic blood pressure (SBP) of ≥3 mmHg. RESULTS: At 24 weeks, dapagliflozin significantly reduced HbA1c (-0.38% [-4.2 mmol/mol]) from baseline (8.18%) compared with a slight increase with placebo from baseline (8.08%) (0.08% [0.9 mmol/mol]). Significantly more patients met the three-item end point with treatment with dapagliflozin than with placebo (11.7% vs. 0.9%, respectively). Changes were maintained over 52 weeks. Although ∼42% of patients were ≥65 years old, similar results were observed in both age-stratified groups. Serious adverse events, hypoglycemia, urinary tract infections, and cardiac disorders were similar between groups. Adverse events of hypotension, dehydration, hypovolemia, genital infection, and renal failure or impairment occurred more often with dapagliflozin treatment. CONCLUSIONS: In this study that evaluated T2D patients who were at high risk for future CVD events, dapagliflozin administration had significantly greater effects in reducing HbA1c, BW, and SBP, without adversely impacting CV safety when compared with placebo treatment.

Safety profile of dapagliflozin for type 2 diabetes: pooled analysis of clinical studies for overall safety and rare events.

BACKGROUND: Dapagliflozin reduces hyperglycaemia in patients with type 2 diabetes mellitus (T2DM) by increasing urinary glucose excretion. OBJECTIVES: This study determined the overall safety profile of dapagliflozin in T2DM. METHODS: Safety of dapagliflozin in pooled analyses of phase IIb/III studies was evaluated. Patients received comparator or dapagliflozin as monotherapy, add-on to antidiabetic therapy, or as initial combination with metformin. Proportions of patients with adverse events (AEs) and prespecified parameters related to previous clinical observations and dapagliflozin's action were assessed. The principal analysis used data from 12 placebo-controlled studies. Rare events were assessed across phase IIb/III studies, including special populations, comparator-controlled trials and ongoing long-term extensions. RESULTS: In placebo-controlled studies, hypoglycaemia was more common with dapagliflozin (11.8 %) than placebo (7.0 %), with imbalance driven by add-on of dapagliflozin to sulfonylurea or insulin. Urinary tract infections (4.8 vs 3.7 %), vulvovaginitis/balanitis and related infections (5.1 vs 0.9 %), and non-serious volume-related events (0.8 vs 0.4 %) occurred more often with dapagliflozin than placebo. No substantial AEs were seen on electrolytes or renal function. Pyelonephritis was rare and balanced among treatments; there were no imbalances in fractures or liver test elevations. Overall incidence of malignancies was balanced between groups. The incidence rate ratios of malignancy in certain organ systems were slightly lower for dapagliflozin (renal tract, female reproductive) and in others were slightly lower for control (breast, prostate, bladder). Most AEs associated with dapagliflozin were mild/moderate and related to the mechanism of action. CONCLUSION: Dapagliflozin has a favourable and predictable tolerability profile, with reported events related to its mechanism of action.

Dapagliflozin added to usual care in individuals with type 2 diabetes mellitus with preexisting cardiovascular disease: a 24-week, multicenter, randomized, double-blind, placebo-controlled study with a 28-week extension.

OBJECTIVES: To assess the efficacy of dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, for the treatment of individuals with type 2 diabetes mellitus (T2DM) and preexisting cardiovascular disease (CVD). DESIGN: Randomized, double-blind, age-stratified (<65 and ≥ 65), 24-week clinical trial with a 28-week extension. SETTING: One hundred seventy-three centers in 10 countries. PARTICIPANTS: Individuals (N = 964) with T2DM, glycosylated hemoglobin (HbA1c) of 7.0% to 10.0%, and documented CVD. INTERVENTION: Dapagliflozin 10 mg/d or placebo was added to usual care. Participants receiving insulin had their total daily insulin dose reduced by 25% at randomization. MEASUREMENTS: Two equal primary end points: change from baseline in HbA1c and proportion of participants achieving a three-item end point (reduction of ≥ 0.5% in HbA1c, ≥ 3% in body weight, and ≥ 3 mmHg in systolic blood pressure) at 24 weeks. RESULTS: Forty-seven percent were aged 65 and older, 7.7% were aged 75 and older, mean duration of T2DM was 13 years, mean baseline HbA1c was 8.1%, and approximately 60% were taking insulin. The placebo-corrected change in HbA1c with dapagliflozin was -0.4% at 24 weeks. Significantly more participants achieved the three-item end point with dapagliflozin (10.0%) than with placebo (1.9%). The placebo-corrected percentage change in body weight for dapagliflozin was -1.9% (-1.8 kg). Similar results were observed in both age strata, and changes were maintained over 52 weeks. More than one-quarter (28.2%) of participants receiving dapagliflozin and 25.3% of those receiving placebo experienced hypoglycemia. More participants receiving dapagliflozin had vulvovaginitis, balanitis, or urinary tract infection. CONCLUSION: When added to a usual background regimen in an older population with advanced T2DM and preexisting comorbid CVD, dapagliflozin improved glycemic control without an increase in hypoglycemic risk, promoted weight loss, and was well tolerated.

Urinary tract infections in patients with diabetes treated with dapagliflozin.

AIMS: Urinary tract infection is common in patients with type 2 diabetes. Possible causative factors include glucosuria, which is a result of treatment with sodium glucose cotransporter 2 (SGLT2) inhibitors. Dapagliflozin is an investigative SGLT2 inhibitor with demonstrated glycemic benefits in patients with diabetes. Data from dapagliflozin multi-trial safety data were analyzed to clarify the association between glucosuria and urinary tract infection. METHODS: Safety data from 12 randomized, placebo-controlled trials were pooled to evaluate the relationship between glucosuria and urinary tract infection in patients with inadequately controlled diabetes (HbA1c >6.5%-12%). Patients were treated with dapagliflozin (2.5, 5, or 10mg) or placebo once daily, either as monotherapy or add-on to metformin, insulin, sulfonylurea, or thiazolidinedione for 12-24weeks. The incidence of clinical diagnoses and events suggestive of urinary tract infection were quantified. RESULTS: This analysis included 3152 patients who received once-daily dapagliflozin (2.5mg [n=814], 5mg [n=1145], or 10mg [n=1193]) as monotherapy or add-on treatment, and 1393 placebo-treated patients. For dapagliflozin 2.5mg, 5mg, 10mg, and placebo, diagnosed infections were reported in 3.6%, 5.7%, 4.3%, and 3.7%, respectively. Urinary glucose levels, but not the incidence of urinary tract infection, increased progressively with dapagliflozin dosage. Most identified infections were those considered typical for patients with diabetes. Discontinuations due to urinary tract infection were rare: 8 (0.3%) dapagliflozin-treated patients and 1 (0.1%) placebo-treated patient. Most diagnosed infections were mild to moderate and responded to standard antimicrobial treatment. CONCLUSIONS: Treatment of type 2 diabetes with once-daily dapagliflozin 5 or 10mg is accompanied by a slightly increased risk of urinary tract infection. Infections were generally mild to moderate and clinically manageable. This analysis did not demonstrate a definitive dose relationship between glucosuria and urinary tract infection.

Vulvovaginitis and balanitis in patients with diabetes treated with dapagliflozin.

BACKGROUND: Vulvovaginitis, balanitis, and related genital infections are common in patients with type 2 diabetes. Glucosuria, which is an outcome of treatment with sodium glucose cotransporter 2 (SGLT2) inhibitors, is among the possible causes. Dapagliflozin, an SGLT2 inhibitor with demonstrated glycemic benefits in patients with diabetes, has been studied across a broad spectrum of patients. Analysis of multi-trial safety data may better define the relationship between glucosuria and genital infection. METHODS: Safety data were pooled from 12 randomized, placebo-controlled Phase 2b/3 trials to analyze the association of glucosuria with genital infection in patients with suboptimally controlled diabetes (HbA1c >6.5%-12%). Patients were randomized to receive dapagliflozin (2.5mg, 5mg, or 10mg) or placebo once daily, either as monotherapy or add-on to metformin, insulin, sulfonylurea, or thiazolidinedione for 12-24weeks. The incidence of clinical diagnoses and of events suggestive of genital infection was evaluated. RESULTS: The pooled safety data included 4545 patients: 3152 who received once-daily dapagliflozin (2.5mg [n=814], 5mg [n=1145], or 10mg [n=1193]) as monotherapy or add-on treatment, and 1393 placebo-treated patients. For dapagliflozin 2.5mg, 5mg, 10mg, and placebo, diagnosed infections were reported in 4.1%, 5.7%, 4.8%, and 0.9%, respectively. Most infections were mild or moderate and responded to standard antimicrobial treatment. Discontinuation due to these events was rare. No clear dose-response relationship between dapagliflozin and genital infection was demonstrated. CONCLUSIONS: Treatment with dapagliflozin 2.5mg, 5mg, or 10mg once daily is accompanied by an increased risk of vulvovaginitis or balanitis, related to the induction of glucosuria. Events were generally mild to moderate, clinically manageable, and rarely led to discontinuation of treatment.

Dapagliflozin versus glipizide as add-on therapy in patients with type 2 diabetes who have inadequate glycemic control with metformin: a randomized, 52-week, double-blind, active-controlled noninferiority trial.

OBJECTIVE: Although initially effective, sulfonylureas are associated with poor glycemic durability, weight gain, and hypoglycemia. Dapagliflozin, a selective inhibitor of sodium-glucose cotransporter 2 (SGLT2), reduces hyperglycemia by increasing urinary glucose excretion independent of insulin and may cause fewer of these adverse effects. We compared the efficacy, safety, and tolerability of dapagliflozin with the sulfonylurea glipizide in patients with type 2 diabetes inadequately controlled with metformin monotherapy. RESEARCH DESIGN AND METHODS: This 52-week, double-blind, multicenter, active-controlled, noninferiority trial randomized patients with type 2 diabetes (baseline mean HbA(1c), 7.7%), who were receiving metformin monotherapy, to add-on dapagliflozin (n = 406) or glipizide (n = 408) up-titrated over 18 weeks, based on glycemic response and tolerability, to ≤10 or ≤20 mg/day, respectively. RESULTS: The primary end point, adjusted mean HbA(1c) reduction with dapagliflozin (-0.52%) compared with glipizide (-0.52%), was statistically noninferior at 52 weeks. Key secondary end points: dapagliflozin produced significant adjusted mean weight loss (-3.2 kg) versus weight gain (1.2 kg; P < 0.0001) with glipizide, significantly increased the proportion of patients achieving ≥5% body weight reduction (33.3%) versus glipizide (2.5%; P < 0.0001), and significantly decreased the proportion experiencing hypoglycemia (3.5%) versus glipizide (40.8%; P < 0.0001). Events suggestive of genital infections and lower urinary tract infections were reported more frequently with dapagliflozin compared with glipizide but responded to standard treatment and rarely led to study discontinuation. CONCLUSIONS: Despite similar 52-week glycemic efficacy, dapagliflozin reduced weight and produced less hypoglycemia than glipizide in type 2 diabetes inadequately controlled with metformin. Long-term studies are required to further evaluate genital and urinary tract infections with SGLT2 inhibitors.

Effects of calcium supplementation on body weight and adiposity in overweight and obese adults: a randomized trial.

BACKGROUND: Some data suggest that increasing calcium intake may help prevent weight gain. OBJECTIVE: To test the hypothesis that calcium supplementation can prevent weight gain in persons who are overweight or obese. DESIGN: Randomized, placebo-controlled trial. Randomization was computer-generated, and allocation was assigned by pharmacy personnel who prepared intervention and placebo capsules. Participants, providers, and those who assessed outcomes were blinded to study group assignment. SETTING: Single research center. PARTICIPANTS: 340 overweight (body mass index [BMI], 25 to <30 kg/m(2)) and obese (BMI > or =30 kg/m(2)) adults (mean age, 38.8 years [SD, 10.5]). INTERVENTION: Calcium carbonate (elemental calcium, 1500 mg/d) (n = 170) or placebo (n = 170) with meals for 2 years. MEASUREMENTS: Changes in body weight and fat mass (primary outcomes). RESULTS: Seventy-five percent of participants completed the trial (78% received calcium; 73% received placebo). There were no statistically or clinically significant differences between the calcium and placebo groups in change in body weight (difference, 0.02 kg [95% CI, -1.64 to 1.69 kg]; P = 0.98), BMI (difference, 0.32 kg/m(2) [CI, -0.41 to 1.02 kg/m(2)]; P = 0.39), or body fat mass (difference, 0.39 kg [CI, -1.04 to 1.92 kg]; P = 0.55). Parathyroid hormone concentrations decreased in the calcium group compared with the placebo group (difference, -0.71 pmol/L [CI, -1.28 to -0.13 pmol/L]). LIMITATION: The study took place at a research center, and its sample was mostly women. CONCLUSION: Dietary supplementation with elemental calcium, 1500 mg/d, for 2 years had no statistically or clinically significant effects on weight in overweight and obese adults. Calcium supplementation is unlikely to have clinically significant efficacy as a preventive measure against weight gain in such patients.

Validation of three food frequency questionnaires to assess dietary calcium intake in adults.

OBJECTIVE: To assess the accuracy of three self-administered food frequency questionnaires (FFQs) to measure dietary calcium intake in healthy adults. DESIGN: Estimates of dietary calcium intake from one previously validated and two recently developed FFQs were compared with those from 7-day food records. SUBJECTS/SETTING: Healthy adults enrolled in an outpatient study of calcium supplementation completed the 36-page Dietary History Questionnaire (DHQ), a 3-page Calcium Questionnaire, and a 1-page Short Calcium Questionnaire. Subjects then completed a 7-day food record. MAIN OUTCOME MEASURES: Differences between calcium intake reported on FFQs and calcium intake from food records were compared. STATISTICAL ANALYSES: Spearman correlations were used to measure associations among variables; Bland-Altman pairwise comparisons were conducted to assess systematic and magnitude biases. RESULTS: We studied 341 subjects, 74.5% female, mean (+/-standard deviation) age of 38+/-11 years and body mass index (calculated as kg/m(2)) of 31.8+/-7.1. Mean (+/-standard deviation) food record calcium intake was 896+/-380 mg/day; data from all three FFQs were positively related to food record calcium intake, but accounted for <40% of the variance in food record dietary calcium intake (DHQ: r(2)=0.21; Calcium Questionnaire: r(2)=0.33; Short Calcium Questionnaire: r(2)=0.37; all P<0.001). The DHQ underestimated daily calcium intake (systematic bias: -94 mg/day, P<0.001; magnitude bias r=-0.40; P<0.001), whereas the Calcium Questionnaire overestimated calcium intake (systematic bias +177 mg/day, P<0.001), but had no significant magnitude bias (r=-0.09; P=0.11). The Short Calcium Questionnaire showed minimal systematic bias (+34 mg/day, P=0.09), but had magnitude bias (r=-0.33; P<0.001). CONCLUSIONS: All three FFQs performed reasonably well at estimating dietary calcium intake compared to food records; each may be appropriate for use in select clinical and research settings.

Rosiglitazone increases LDL particle size and buoyancy and decreases C-reactive protein in patients with type 2 diabetes on statin therapy.

A substantial number of individuals with type 2 diabetes mellitus (T2DM) demonstrate a predominance of small dense low-density lipoprotein (sdLDL), which is associated with an increased risk of cardiovascular disease (CVD). In some cases, sdLDL persists after treatment with a statin to reduce levels of LDL. The effect of the addition of a thiazolidinedione, rosiglitazone (RSG) (4 mg/day or 8 mg/day) to statin therapy on LDL phenotype and C reactive protein (CRP) levels was investigated in a 12- week, placebo-controlled study of 72 T2DM patients who were well controlled and on a statin, but who had persistently predominant sdLDL. Addition of RSG 8 mg to statin therapy significantly increased LDL buoyancy (relative flotation +0.014, p = 0.003) and LDL particle size (+4.2A, p = 0.001) from baseline and relative to the change with placebo (+0.014 and +3.8A; p = 0.03 and p = 0.04, respectively), and was associated with a non-significant decrease in sdLDL. RSG 8 mg moderately, but significantly, increased total cholesterol (by 12.2%, p = 0.004), LDL-cholesterol (11.2%, p = 0.02) and intermediate-density lipoprotein (IDL)-cholesterol from baseline but did not increase total or LDL apolipoprotein B. RSG 4 mg and 8 mg significantly reduced CRP compared with placebo (-44.9% and -48.0%; p = 0.008 and p = 0.004, respectively), and significantly reduced insulin resistance and fasting plasma glucose from baseline. Addition of RSG to statin therapy may further reduce cardiovascular risk by improving the LDL phenotype, as well as reducing insulin resistance and CRP levels. However, the increase in IDL may be proatherogenic and must be considered when assessing the benefits of rosiglitazone.

The prevalence of hypovitaminosis D and secondary hyperparathyroidism in obese Black Americans.

CONTEXT: Both obesity (body mass index, BMI > or = 30 kg/m2) and Black race are associated with a higher risk of vitamin D deficiency and secondary hyperparathyroidism. We hypothesized the risk of hypovitaminosis D would therefore be extraordinarily high in obese Black adults. OBJECTIVE: To study the effects of race and adiposity on 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (iPTH). DESIGN, SETTING AND PARTICIPANTS: Cross-sectional study of 379 Black and White adults from the Washington D.C. area. BMI ranged from 19.9 to 58.2 kg/m2. MAIN OUTCOME MEASURES: Prevalence of hypovitaminosis D [25(OH)D < 37.5 nmol/l] and secondary hyperparathyroidism [25(OH)D < 37.5 nmol/l with iPTH > 4.2 pmol/l]. RESULTS: Obese Black subjects had lower mean 25(OH)D, 40.3 (SD, 20.3) nmol/l, compared with obese Whites, 64.5 (29.7), P < 0.001, nonobese Blacks, 53.3 (26.0), P = 0.0025 and nonobese Whites, 78.0 (33.5), P < 0.001. The prevalence of hypovitaminosis D increased with increasing BMI, and was greater (P < 0.001) in Blacks than Whites within all BMI categories examined. Among subjects with BMI > or = 35 kg/m2, 59% of Blacks vs 18% of Whites had hypovitaminosis D (odds ratio 6.5, 95% confidence interval 3.0-14.2). iPTH was negatively correlated with 25(OH)D (r = -0.31, P < 0.0001), suggesting those with hypovitaminosis D had clinically important vitamin D deficiency with secondary hyperparathyroidism. For secondary hyperparathyroidism 35.2% of Blacks met the criteria, compared to 9.7% of Whites (OR 3.6, CI 1.5-98.8). CONCLUSIONS: Obese Black Americans are at particularly high risk for vitamin D deficiency and secondary hyperparathyroidism. Physicians should consider routinely supplementing such patients with vitamin D or screening them for hypovitaminosis D.

The relationship between obesity and serum 1,25-dihydroxy vitamin D concentrations in healthy adults.

Several previous reports of small cohorts have found significantly higher serum 1,25-dihydroxy vitamin D (1,25-vit D) in obese compared with nonobese whites. Based on these reports and on recent in vitro studies of adipocytes which suggest that administration of 1,25-vit D can stimulate lipogenesis and inhibit lipolysis, some investigators have proposed that high 1,25-vit D may play a role in promoting or maintaining adipocyte triglyceride stores in obese adults. To test the hypothesis that obesity is commonly associated with increased 1,25-vit D, we examined the relationships between calciotropic hormones and body adiposity in a large cohort of healthy adults. Serum intact PTH, 25-hydroxy vitamin D, and 1,25-vit D were measured in the postabsorptive state in 302 healthy adults who were Caucasian (n = 190; 71% female), African-American (n = 84; 89% female), and of other race/ethnicity (n = 28; 61% female). Results from the 154 obese subjects [body mass index (BMI) 37.3 +/- 5.8 kg/m(2); range, 30.1-58.2 kg/m(2)] were compared with those from 148 nonobese (BMI 25.6 +/- 2.9 kg/m(2); range, 18.0-29.9 kg/m(2)) age-, race-, and sex-matched participants. Body composition was measured by dual energy x-ray absorptiometry. Serum intact PTH was positively correlated with both BMI (r = 0.42; P < 0.0001) and body fat mass (r = 0.37; P < 0.0001). Serum 25-hydroxy vitamin D was negatively correlated with BMI (r = -0.4; P < 0.0001) and body fat mass (r = -0.41; P < 0.0001). Serum 1,25-vit D was also negatively correlated with BMI (r = -0.26; P < 0.0001) and body fat mass (r = -0.25; P = 0.0001). Serum 1,25-vit D was significantly lower in obese than nonobese subjects (105.7 +/- 41.1 vs. 124.8 +/- 36.7 pmol/liter; P < 0.0001) in both Caucasian and African-American adults. We conclude that, because 1,25-vit D concentrations fall with increasing adiposity, it appears unlikely that elevation in 1,25-vit D is an important hormonal mechanism causing or maintaining obesity in adults.

Calcium intake and adiposity.

Limited epidemiologic and experimental data support the possibility that dietary calcium intake plays a role in human body weight regulation. The aim of this review was to present the data from human studies that link calcium and dairy intake to body weight, describe the existing evidence for an effect of calcium intake on body weight from animal models of obesity, present evidence of a role for intracellular calcium in the regulation of lipogenesis and lipolysis, elucidate the potential suggested relation between dietary calcium intake and intracellular calcium concentrations, and outline the effects of calcium supplementation on dietary fat absorption. We suggest that these data support the need for large, population based clinical trials to assess the effects of supplemental calcium and other components of dairy products on human body weight.

Indices of insulin action, disposal, and secretion derived from fasting samples and clamps in normal glucose-tolerant black and white children.

OBJECTIVE: To validate fasting indices of insulin sensitivity and secretion in a diverse pediatric population against gold standard estimates from euglycemic and hyperglycemic clamps. RESEARCH DESIGN AND METHODS: A total of 31 children (mean BMI 25.1 +/- 4.9 kg/m(2), mean age 8.7 +/- 1.4 years, 15 girls and 16 boys, 12 black and 19 white) underwent euglycemic and hyperglycemic clamps 2-6 weeks apart to derive insulin sensitivity indices (SI (Eug clamp) and SI (Hyper clamp)). Fasting samples were used to derive the homeostasis model assessment of insulin resistance index (HOMA-IR), HOMA of percent beta-cell function (HOMA-B%), quantitative insulin sensitivity check index (QUICKI), insulinogenic index, antilipolytic insulin sensitivity index (ISI-FFA), and C-peptide-to-insulin ratio. RESULTS: The QUICKI correlated best with SI (Eug clamp) (r = 0.69, P < 0.05) and had greater correlations to SI (Eug clamp) than did either SI (Hyper clamp) (r = 0.45, P < 0.05) or the HOMA-IR (r = -0.51, P < 0.05). Both fasting insulin and the insulinogenic index correlated well with first- and steady-phase insulin secretion (r's from 0.79 to 0.86, P < 0.05). HOMA-B% was not as highly correlated (r = 0.69-0.72, P < 0.05). Fasting C-peptide-to-insulin ratio was not significantly correlated with clamp-derived metabolic clearance rate of insulin. ISI-FFA was not correlated with the degree of free fatty acid suppression obtained from the clamps. CONCLUSIONS: The QUICKI, fasting insulin, and the insulinogenic index all closely correlate with corresponding clamp-derived indices of insulin sensitivity and secretion in this diverse pediatric cohort. These results, if replicated in similarly diverse populations, suggest that estimates based on fasting samples can be used to rank order insulin secretion and sensitivity in pediatric cohorts.