Bone effects of rosiglitazone in HIV-infected patients with lipoatrophy.

OBJECTIVES: Thiazoledinediones increase limb fat in HIV+ patients with lipoatrophy. However, their use in the general population has been associated with bone loss and fracture. We sought to determine the effects of rosiglitazone on bone metabolism in HIV-infected patients. METHODS: HIV+ patients with lipoatrophy were randomized to rosiglitazone versus placebo for 48 weeks in a double-blind, placebo-controlled trial. Limb fat, bone mineral density (BMD), bone formation markers (procollagen type 1 amino-terminal propeptide [P1NP], osteocalcin [OC]) and bone resorption markers (C-terminal telopeptide of type I collagen [CTX]) were measured, along with receptor activator for nuclear factor kappa ß ligand (RANKL), osteoprotegerin (OPG), and inflammatory cytokines. RESULTS: Seventy-one subjects were randomized to rosiglitazone or placebo: 17% female and 51% white. Total BMD did not change significantly in either group. In the rosiglitazone group, P1NP showed statistically significant decreases at 24 and 48 weeks; however, changes compared to placebo were only significant at 24 weeks. OC decreased significantly in the rosiglitazone group at 24 weeks, but there were no between-group differences. CTX, RANKL, or OPG did not change for either group. Multivariable regression within the rosiglitazone arm showed P1NP changes were inversely associated with limb fat changes, protease inhibitors, and tenofovir use. CONCLUSION: Rosiglitazone use was associated with decreased bone formation, but it did not alter bone resorption or total BMD. The increase in limb fat that accompanies rosiglitazone use appears to be associated with decreased osteoblast activity. Further studies are needed to determine the effect of thiazoledinediones on bone health in HIV-infected persons.

[Insulin-induced lipoatrophy in children]. / InsuLiinihoidon lapsille aiheuttama lipoatrofia.

Insulin-induced lipoatrophy is a rare but serious complication of insulin treatment. Its incidence decreased during 1970' and 1980's, but several reports of this phenomenon have again recently been published. Traditional treatment options have included injecting insulin or pump cannula to the area surrounding the lipoatrophy or changing the insulin type or preparation. In this report we present 4 children who developed severe lipoatrophy during insulin pump treatment. Changing injection sites did not help but lipoatrophy disappeared in one patient after changing the insulin preparation. In the three other patients no new atrophy sites have appeared after change in insulin preparation or simultaneous treatment with local pimecrolimus or sodium cromoglicate.

Adipose tissue is required for the antidiabetic, but not for the hypolipidemic, effect of thiazolidinediones.

There is uncertainty about the site(s) of action of the antidiabetic thiazolidinediones (TZDs). These drugs are agonist ligands of the transcription factor PPAR gamma, which is abundant in adipose tissue but is normally present at very low levels in liver and muscle. We have studied the effects of TZDs in A-ZIP/F-1 mice, which lack white adipose tissue. The A-ZIP/F-1 phenotype strikingly resembles that of humans with severe lipoatrophic diabetes, including the lack of fat, marked insulin resistance and hyperglycemia, hyperlipidemia, and fatty liver. Rosiglitazone or troglitazone treatment did not reduce glucose or insulin levels, suggesting that white adipose tissue is required for the antidiabetic effects of TZDs. However, TZD treatment was effective in lowering circulating triglycerides and increasing whole body fatty acid oxidation in the A-ZIP/F-1 mice, indicating that this effect occurs via targets other than white adipose tissue. A-ZIP/F-1 mice have markedly increased liver PPAR gamma mRNA levels, which may be a general property of fatty livers. Rosiglitazone treatment increased the triglyceride content of the steatotic livers of A-ZIP/F-1 and ob/ob mice, but not the "lean" livers of fat-transplanted A-ZIP/F-1 mice. In light of this evidence that rosiglitazone acts differently in steatotic livers, the effects of rosiglitazone, particularly on hepatic triglyceride levels, should be examined in humans with hepatic steatosis.

Rethinking leptin and insulin action: therapeutic opportunities for diabetes.

Leptin is an adipocyte-derived hormone that primarily acts in the hypothalamus and plays a key role in the regulation of food intake, body weight, energy expenditure and neuroendocrine function. Leptin has direct peripheral effects on several tissues, and it may be independently involved in insulin secretion and action besides its effects on body weight regulation. Basal plasma leptin and insulin concentrations correlate with each other. Insulin and glucose appear to increase leptin secretion. In turn, leptin increases peripheral insulin sensitivity while decreasing insulin secretion from pancreatic beta cells. Leptin increases skeletal muscle glucose uptake and oxidation, and suppresses hepatic glucose output. Effects of leptin on lipid metabolism might reduce lipotoxicity and therefore contribute to the improvement of hepatic, skeletal and whole body insulin sensitivity. Leptin is the first adipokine used in the treatment of hypoleptinemic clinical disorders. Although leptin therapy has limited success in common obesity, it has impressive effects in congenital leptin deficiency, lipoatrophic diabetes and syndromes of severe insulin resistance. Leptin has been reported to ameliorate hyperinsulinemia and diabetes in the clinical setting of congenital leptin deficiency. It also improves hyperglycemia, insulin resistance, hyperinsulinemia, dyslipidemia and hepatic steatosis in lipoatrophic diabetes. These promising results warrant clinical trials to test the hypothesis that leptin alone or with classical antidiabetic agents may potentially be beneficial in the treatment of hypoleptinemic non-obese individuals with glucose intolerance and diabetes. This review summarizes the clinical applications of leptin, particularly emphasizing the effects of leptin on glucose homeostasis.

Resistin levels in human immunodeficiency virus-infected patients with lipoatrophy decrease in response to rosiglitazone.

Resistin is a recently recognized adipocytokine thought to contribute to insulin resistance. We determined resistin levels and metabolic parameters in 24 HIV-infected men and women with lipoatrophy and hyperinsulinemia and studied the effect of 12 wk of the peroxisome proliferator-activated receptor-gamma agonist rosiglitazone (4-8 mg/d) on resistin in these subjects. Participants completed metabolic testing before and after rosiglitazone including fasting determination of resistin, adiponectin, and leptin levels, serum inflammatory markers, and hyperinsulinemic euglycemic clamp testing. Resistin concentration decreased significantly after rosiglitazone (12.17 +/- 1.15 ng/ml to 10.23 +/- 1.05 ng/ml; P = 0.02), in conjunction with significant increases in adiponectin- (P < 0.001) and insulin- stimulated glucose disposal (P = 0.004). Leptin levels, as well as TNF-alpha, did not change with rosiglitazone. In summary, among HIV-infected subjects with insulin resistance and lipoatrophy, resistin levels decreased significantly after rosiglitazone. Further investigation into the physiological role of this peroxisome proliferator-activated receptor-gamma-responsive adipocytokine in the metabolic abnormalities associated with HIV is warranted.

Transgenic overexpression of leptin rescues insulin resistance and diabetes in a mouse model of lipoatrophic diabetes.

Lipoatrophic diabetes is caused by a deficiency of adipose tissue and is characterized by severe insulin resistance, hypoleptinemia, and hyperphagia. The A-ZIP/F-1 mouse (A-ZIPTg/+) is a model of severe lipoatrophic diabetes and is insulin resistant, hypoleptinemic, hyperphagic, and shows severe hepatic steatosis. We have also produced transgenic "skinny" mice that have hepatic overexpression of leptin (LepTg/+) and no adipocyte triglyceride stores, and are hypophagic and show increased insulin sensitivity. To explore the pathophysiological and therapeutic roles of leptin in lipoatrophic diabetes, we crossed LepTg/+ and A-ZIPTg/+ mice, producing doubly transgenic mice (LepTg/+:A-ZIPTg/+) virtually lacking adipose tissue but having greatly elevated leptin levels. The LepTg/+:A-ZIPTg/+ mice were hypophagic and showed improved hepatic steatosis. Glucose and insulin tolerance tests revealed increased insulin sensitivity, comparable to LepTg/+ mice. These effects were stable over at least 6 months of age. Pair-feeding the A-ZIPTg/+ mice to the amount of food consumed by LepTg/+:A-ZIPTg/+ mice did not improve their insulin resistance, diabetes, or hepatic steatosis, demonstrating that the beneficial effects of leptin were not due to the decreased food intake. Continuous leptin administration that elevates plasma leptin concentrations to those of LepTg/+:A-ZIPTg/+ mice also effectively improved hepatic steatosis and the disorder of glucose and lipid metabolism in A-ZIP/F-1 mice. These data demonstrate that leptin can improve the insulin resistance and diabetes of a mouse model of severe lipoatrophic diabetes, suggesting that leptin may be therapeutically useful in the long-term treatment of lipoatrophic diabetes.

Ectodermal dysplasia, lipoatrophy, diabetes mellitus, and amastia: a second case of the AREDYLD syndrome.

A 19-year-old female with ectodermal dysplasia, lipoatrophy, diabetes mellitus, and amastia is described. This complex of symptoms is very similar to that of a case published by Pinheiro et al [1983] under the acronym of AREDYLD syndrome.

Very low-density lipoprotein metabolism in an unusual case of lipoatrophic diabetes.

Complete acquired lipoatrophic diabetes (LD) is characterized by nonketotic insulin-resistant diabetes, elevated very low-density lipoprotein (VLDL) triglyceride (TG) levels, and absent subcutaneous fat. We studied a young child in whom LD atypically developed after the onset of type 1 diabetes mellitus. On uncontrolled home diet the patient had triglyceride levels over 1,000 mg/dL on multiple occasions. In order to demonstrate the effects of caloric and dietary-fat restriction on VLDL metabolism, 3H-glycerol and autologous 125I-VLDL were used to quantitate the turnover of VLDL-TG and VLDL-apolipoprotein B (apo B) during two periods of caloric restriction. Consumption of a 900-kcal 40-g fat diet resulted in a plasma triglyceride level of 1383 mg/dL (ten-fold elevation). This hypertriglyceridemia was associated with markedly increased production rates of both VLDL-TG (73.7 mg/kg/h) and VLDL-apo B (126.9 mg/kg/d). Consumption of a 900-kcal 25-g fat diet resulted in a plasma TG level of 663 mg/dL. This reduction in plasma TG was associated with a 40% decrease in VLDL-TG production rate (PR) (45.1 mg/kg/h). There was no change in the production rate (PR) of VLDL-apo B. The hypertriglyceridemia in this patient was due to marked over production of VLDL. Furthermore, the studies demonstrate: (1) the independent benefits of caloric and dietary-fat restriction in the treatment of LD, and (2) that fat restriction lowered plasma triglyceride by its effect on the VLDL-TG production rate.

Lipodystrophic diabetes mellitus. Investigations of lipoprotein metabolism and the effects of omega-3 fatty acid administration in two patients.

We investigated the metabolic effects of omega-6 (safflower oil) and omega-3 (fish oil) fatty acid-enriched diets (65% carbohydrate, 20% fat) in two patients with a syndrome of diabetes mellitus, lipodystrophy, acanthosis nigricans, chylomicronemia, and abdominal pain. 3H-glycerol was used to evaluate triglyceride-rich lipoprotein-triglyceride (TRLP-TG) metabolism, and changes in glucose and insulin dynamics were also studied. On the omega-6 diet, both subjects demonstrated four- to five-times normal rates of TRLP-TG production and glycerol biosynthesis, and striking decrements in the fractional catabolic rate (FCR) for TRLP-TG and TRLP-particles. Both subjects had elevations in nonesterified fatty acid (NEFA) concentrations. In one patient, the omega-3 diet markedly decreased serum triglycerides and newly synthesized triglyceride glycerol production, in association with a fall in NEFA. In both subjects, plasma glycerol reutilization for triglyceride synthesis, normal on the omega-6 diet, was abolished on the omega-3 regimen. Plasma postheparin lipolytic activity was normal on both diets. On the omega-3 diet, xanthomas and hepatomegaly decreased and, in the patient who had no reduction in serum triglycerides, pancreatitis attacks virtually ceased. Mean 24-hour serum glucose levels were higher, and both basal and peak C-peptide responses to a carbohydrate meal were blunted on the omega-3 diet. One patient became ketonuric. We conclude the cause of hypertriglyceridemia in these patients was due to increased lipid synthesis and hypothesize that this is secondary to high plasma concentrations of NEFA. In addition, an omega-3 diet in these subjects inhibited insulin secretion and worsened glucose tolerance.

Improved acanthosis nigricans with lipodystrophic diabetes during dietary fish oil supplementation.

Acanthosis nigricans is well recognized in its clinical association with several types of insulin-resistant syndromes, and skin involvement is usually unresponsive to local treatment or management of diabetes. A young woman with a lipodystrophic form of diabetes, hypertriglyceridemia, and severe generalized acanthosis nigricans was placed on a diet with fat supplementation in the form of omega-3-fatty-acid-rich fish oil. She was observed to have striking improvement in the appearance and extent of acanthosis nigricans while receiving this regimen. This occurred despite continued therapy with niacin (nicotinic acid), an agent associated with acanthosis nigricanslike skin changes.

Lipoatrophic diabetes mellitus treated by continuous subcutaneous insulin infusion.

This case report evaluated continuous subcutaneous insulin infusion (CSII) in a 50-year-old Caucasian woman who suffered from partial lipodystrophy and severely insulin-resistant diabetes mellitus. Intensive insulin therapy (three daily injections) failed to provide good metabolic control (HbA1c ranging from 10 to 12%). Even though the patient had very thin subcutaneous tissue, CSII was initiated and proved highly efficient, improving blood glucose control considerably (HbA1c ranging from 7.5 to 8.5%), but with no decrease in the daily insulin requirement (2 IU/kg/day). Plasma triglycerides were also greatly improved (from 16.5 to 3.7 mmol/l). Thus, this study indicates that CSII is suitable for patients with lipoatrophy and insulin-resistant diabetes mellitus.

Successful outcome of pregnancy in a patient with generalized lipoatrophic diabetes mellitus.

OBJECTIVE: To report the first known case of a successful outcome of pregnancy in a patient with generalized lipoatrophic diabetes. METHODS: We present a detailed case report of a patient who achieved and successfully completed a pregnancy despite having lipoatrophic diabetes. RESULTS: With careful attention to glycemic control with use of U-500 insulin and strict avoidance of dietary fat, a 23-year-old woman with lipoatrophic diabetes maintained a pregnancy to 28 weeks. The infant weighed 1,235 g and was devoid of serious metabolic complications. Three months after childbirth, the patient died of gastrointestinal bleeding. CONCLUSION: We are not aware of any previously published report of a successful pregnancy in a patient with generalized, acquired lipoatrophic diabetes. Because of the involvement of multiple organ systems in generalized lipoatrophic diabetes, female patients should be thoroughly advised of the serious pregnancy-associated risks to both the mother and the fetus and the need for extremely close monitoring.

[Lipoatrophic diabetes with acanthosis nigricans. Prolonged blood glucose normalization by continuous infusion of insulin]. / Diabète lipoatrophique avec acanthosis nigricans. Normalisation glycémique prolongée par infusion continue d'insuline.

Insulin resistance is a permanent feature of lipoatrophic diabetes, the resistance being almost regularly stubborn. We report the case of a 23-year old unmarried woman with generalized lipoatrophy and Acanthosis nigricans. Seven years after a diabetes resistant to all treatments was diagnosed, blood glucose levels were permanently around 25 mmol/l. Multiple and severe micro- and macroangiopathies were present. Partial resistance to insulin was demonstrated. This resistance could not be explained by abnormalities in anti-insulin hormones nor by a decrease in the number or affinity of insulin receptors, which suggested an intracellular abnormality below membrane receptors. Sustained control of glycaemia at a normal level was achieved by continuous infusion of insulin in high doses. It would appear that optimum insulin therapy using an insulin pump would offer hopes of therapeutic success in this particular form of insulin resistance.

[Lipoatrophic diabetes. A therapeutic challenge]. / Diabetes lipoatrófica. Un reto terapéutico.

Congenital generalised lipodystrophy is a rare autosomal recessive disorder characterised by a marked deficiency of adipose tissue and usually recognised at birth. This disorder is associated with early development of metabolic complications such as hypertriglyceridemia, hepatic steatosis, and insulin resistance. These complications ultimately lead to fatal events as a consequence of early atherosclerosis, lipoatrophic diabetes and hepatic cirrhosis. The authors report the case of a patient diagnosed, based on clinical and laboratory findings, in the first year of life. The established diagnosis was then confirmed by identifying a mutation in the BSCL2 gene. Because the hypertriglyceridemia and diabetes were refractory to treatment, the authors present this case in order to reflect on the best therapeutic management of this pathology.

Continuous subcutaneous insulin infusion allows tolerance induction and diabetes treatment in a type 1 diabetic child with insulin allergy.

AIM: Insulin allergy is a rare but serious and challenging condition in patients with type 1 diabetes (T1D). This is a case report of an 8-year-old boy with T1D and an allergy to insulin. CASE REPORT: Three months after being diagnosed with T1D, the patient developed progressive skin reactions to insulin, characterized by small 1.5-cm pruritic wheals at injection sites that persisted for several days. Seven months after diagnosis, he experienced two episodes of generalized urticaria with systemic symptoms that were seen within a few seconds of insulin injection. Examination revealed lipoatrophy of the thighs. Intradermal skin tests were positive for protamine, glargine and lispro. The patient was started on a continuous subcutaneous insulin infusion (CSII) tolerance induction protocol, consisting of a very low basal rate that was progressively increased, with the first bolus given under medical supervision, and was well tolerated for 4 months. After this period of time, the skin wheals reappeared, localized to the infusion sites, but without urticaria or any other generalized reactions. Intradermal skin tests were repeated and were again positive. Serum insulin-specific IgE measured 30 months after the first allergic reactions were positive. After 3 years, pump therapy is ongoing and blood glucose control has remained relatively good (HbA1c 7.6%). CONCLUSION: In T1D children with insulin allergy, CSII can successfully be used to both induce insulin tolerance and allow diabetes insulin therapy, although insulin desensitization cannot always be fully achieved. The induction protocol was easily manageable partly due to the "honeymoon" period that the patient was still in, but it should nonetheless be used even when the patient has higher insulin requirements.