Incidence and Clinical Significance of Lactose Malabsorption in Adult Coeliac Disease

Fifty-one adult patients with coeliac disease, verified by a proximal small-intestinal biopsy, were investigated. Before treatment with a gluten-free and low-lactose diet 52% showed a slight rise in blood glucose during the lactose tolerance test. Seventy-nine per cent of these patients had watery stools, and 88% had three or more bowel movements a day—statistically significantly different from the coeliac patients with a normal lactose tolerance test. After treatment 12% had a flat lactose tolerance curve. Half of them (6%) had specific lactase deficiency. This is approximately the incidence of lactose malabsorption in the general Danish population. The small-intestinal disaccharidases and alkaline phosphatase levels were severely depressed before treatment. After treatment the activities increased, but not to normal. We conclude that lactose malabsorption is a clinically important condition in many patients with untreated coeliac disease, giving rise to more frequent and more watery stools. In well-treated coeliac disease lactose malabsorption is not commoner than in the general population. The lactose activity in a proximal intestinal biopsy specimen was found to be an unreliable indicator of lactose malabsorption in coeliac disease.     

Carbohydrate Malabsorption Syndromes and Early Signs of Mental Depression in Females

Fructose and lactose malabsorption are characterized by impaired duodenal fructose transport or by the deficiency of mucosal lactase, respectively. As a consequence, the nonabsorbed saccharides reach the colon, where they are broken down by bacteria to short fatty acids, CO₂, and H₂. Bloating, cramps, osmotic diarrhea, and other symptoms of irritable bowel syndrome are the consequence and can be seen in about 50% of carbohydrate malabsorbers. We have previously shown that fructose as well as lactose malabsorption were associated with signs of mental depression. It was therefore of interest to investigate possible interactions between fructose and lactose malabsorption and their influence on the development of signs of depression. In all, 111 otherwise healthy volunteers (81 females and 30 males) with gastrointestinal complaints were analyzed by measuring breath H₂ concentrations after an oral dose of 50 g lactose and of 50 g fructose one week apart. They were classified as normals, isolated fructose malabsorbers, isolated lactose malabsorbers, and combined fructose/lactose malabsorbers. All patients filled out a Becks depression inventory–questionnaire. Twenty-five individuals (22.5%) were neither fructose nor lactose malabsorbers (group 1), 69 (62.2%) were only fructose malabsorbers (group 2), 4 (3.6%) were only lactose malabsorbers (group 3), and 13 (11.7%) presented with fructose and lactose malabsorption together (group 4). Isolated fructose malabsorption and combined fructose/lactose malabsorption was significantly associated with a higher Becks depression score. Further analysis of the data show that this association was strong in females (P < 0.01), but there was no such association between carbohydrate malabsorption and early signs of depression in males. In conclusion, the data confirm that fructose malabsorption may play a role in the development of mental depression in females and additional lactose malabsorption seems to further increase the risk for development of mental depression.     

Lactose malabsorption, irritable bowel syndrome and self-reported milk intolerance

BACKGROUND: The relationship between lactose malabsorption, irritable bowel syndrome and development of intestinal symptoms is unclear, especially when the ingested dose of milk is small. Thus, the role of hydrogen breath testing in the diagnostic work-up of patients with nonspecific intestinal symptoms is still debated. AIMS: To establish the relationship between lactose malabsorption, severe self-reported milk intolerance, irritable bowel syndrome and related symptoms. METHODS: The prevalence of lactose malabsorption was prospectively assessed by means of a hydrogen breath test in 839 patients (503 with irritable bowel syndrome, based on the Rome criteria, regularly consuming milk, and 336 subjects who identified themself as milk intolerant, after an oral load of 25 g lactose). The test was considered "positive" when a hydrogen peak exceeding 20 ppm over baseline values was observed in two or more samples. Attempts were also made to establish whether the predominant presenting symptom (diarrhoea, constipation, alternating diarrhoea and constipation, pain and gaseousness) might be helpful in predicting the outcome of the breath test. RESULTS: The prevalence of a positive breath test was comparable in the two groups (337 patients with irritable bowel syndrome (66.9%) vs 240 patients with milk intolerance (71.4%)). The same holds true for the first peak of hydrogen excretion, total hydrogen output and prevalence of symptoms during, and in the four hours after, the test. The predominant presenting symptom was not useful for predicting outcome of the test either in regular milk users or in milk intolerant subjects. CONCLUSIONS: The almost identical results of the lactose breath test of patients with irritable bowel syndrome and subjects with self-reported milk intolerance suggests that the two conditions overlap to such an extent that the clinical approach should be the same. A lactose breath test should always be included in the diagnostic work-up for irritable bowel syndrome, as fermentation of malabsorbed lactose is likely responsible for triggering symptoms. Conversely, lactase deficiency is probably irrelevant in most subjects not affected by irritable bowel syndrome, within a moderate milk consumption.     

Fructose and Sorbitol Malabsorption in Ambulatory Patients with Functional Dyspepsia Comparison with Lactose Maldigestion/Malabsorption

The aim of this study was to study sugarmaldigestion/malabsorption in patients with functionaldyspepsia using H breath testing. End-expiratory breathH after separate 2 challenges with lactose (25 g), fructose (25 g), and sorbitol (5 g) were usedto determine malabsorption, as well as small boweltransit time (SBTT). Five hundred twenty patients withfunctional dyspepsia received all three challenges. Smaller groups were also tested after lactulose(10 g, N = 36) and glucose (50 g, N = 90) challenges.Fructose and sorbitol were closely linked with respectto absorption and malabsorption status. Only in the case of lactose maldigestion/malabsorption wasthere a greater than random prevalence of malabsorption(P < 0.001) for fructose and sorbitol. In contrast tolactose, ethnic origin did not influence fructose or sorbitol malabsorption, and femalespredominated among fructose and sorbitol malabsorbers.In Jews, the prevalence of lactosemaldigestion/malabsorption decreased in the age group of25-55 and subsequently rose after 55, while fructose and sorbitolmalabsorption decreased progressively with advancingage. With respect to small bowel transit time (SBTT), inthe case of sorbitol and lactulose, it was significantly greater (P < 0.05) than those for fructoseand lactose. Multiple sugar malabsorptions are commonwhen lactose maldigestion/malabsorption ispresent.     

Development, Validation, and Applicability of a Symptoms Questionnaire for Lactose Malabsorption Screening

Lactase deficiency has a high prevalence worldwide. Thus, a valid symptom scale would be a useful tool for identifying patients with lactose malabsorption. Objective To develop, validate, and apply a symptoms questionnaire on lactose malabsorption to identify lactose malabsorbers diagnosed with the gold-standard hydrogen breath test. Methods In the first part of the study, 292 patients completed a questionnaire at the end of a 50-g lactose breath test. The questionnaire included five items (diarrhea, abdominal cramping, vomiting, audible bowel sounds, and flatulence or gas) scored on a 10-cm visual analogue scale. In the second part of the study, 171 patients completed the questionnaire twice: first, according to their opinion when consuming dairy products at home and second, after a 50-g lactose breath test. Patients were grouped as absorbers or malabsorbers according to the result of the breath test. Results Diarrhea, abdominal cramping, and flatulence were scored significantly higher in malabsorbers than in absorbers. Total score of the symptomatic questionnaire was significantly higher in malabsorbers (17.5 versus 3.0, P < 0.01). According to receiver operator characteristics (ROC) analysis, the most discriminant cut-off of the total score to identify lactose malabsorption was 6.5 (sensitivity 0.75, specificity 0.67). In 58 malabsorbers the effect size of the questionnaire to determine sensitivity to change was 1.32. In the second part of the study, scoring of the home questionnaire was higher than after the lactose-breath test. The lactose malabsorbers rate was higher according to the home questionnaire than after the lactose breath test (72% versus 52%). The home questionnaire had excellent sensitivity (0.82) but low specificity (0.35). Conclusion We developed and validated a five-item symptoms questionnaire for lactose malabsorption. This is a valid test that permits patients with a total score lower than 7 to be excluded from future studies.     

The Colon in Carbohydrate Malabsorption: Short-Chain Fatty Acids,pH, and Osmotic Diarrhoea

Holtug K, Clausen MR, Hove H, Christiansen J, Mortensen PB. The colon in carbohydrate malabsorption: short-chain fatty acids, pH, and osmotic diarrhoea. Scand J Gastroenterol 1992;27:545-552.

Short-chain (C₂-C₆) fatty acids (SCFA) are the major anions in colonic contents and the result of anaerobic fermentation of mainly saccharides. The effects and regulation of saccharide fermentation were studied in vitro and in vivo. In vitro faecal incubation was used to study the effects of lactose, glucose, and galactose and of pH on SCFA formation. Changing the pH to below 5 or above 11 abolished SCFA formation in the faecal incubates; in the pH 5-9 interval SCFA production was high, with only minor pH dependence. Adding glucose, galactose, or lactose to the incubation system increased SCFA production, but at high saccharide concentrations (100-300 mmol/1) SCFA formation was inhibited by the pH change. In vivo disaccharide malabsorption with increasing doses of lactulose caused a decrease in faecal pH to < 5, values inhibitory to fermentation, before the appearance of carbohydrate in faeces. In 6 of 12 volunteers diarrhoea occurred suddenly and was caused by malabsorbed non-fermented carbohydrate. The six other volunteers had a gradual increase in faecal output with lactulose dose and developed diarrhoea before the appearance of saccharide in faeces. The intake of lactulose tolerated before diarrhoea ensued varied between individuals, with the majority having diarrhoea of more than 1 1/day at 160 g lactulose per day. At this dose SCFA absorption was estimated to be in the range 550 to 1150mmol/day.     

Transient Lactose Malabsorption in Patients Affected by Symptomatic Uncomplicated Diverticular Disease of the Colon

Lactose malabsorption (LM) may be secondary to several small bowel diseases, and small intestinal overgrowth (SIBO) may be one of them. We looked for a correlation between symptomatic diverticular disease of the colon and LM and assessed whether this correlation may be related to SIBO. Ninety consecutive patients (pts; 39 males, 51 females; mean age, 67.2 years; range, 32–91 years) affected by symptomatic uncomplicated diverticular disease of the colon were evaluated to assess orocecal transit time (OCTT), SIBO, and LM by lactulose and lactose H₂ breath test (H₂-BT) at entry and after 8 weeks of treatment. OCTT was delayed in 67 of 90 pts (74.44%). Fifty-three of 90 pts (58.88%) showed SIBO, and OCTT was normal in 23 of 90 pts (25.56%). LM was diagnosed in 59 of 90 pts (65.55%): 49 of 59 (71.74%) were simultaneously affected by SIBO and delayed OCTT (and thus 49 of 53 pts [92.45%] with delayed OCTT and SIBO were affected by LM); 3 of 59 pts (5.09%) showed only delayed OCTT; 7 of 59 pts (11.86%) did not show either SIBO or delayed OCTT. The association of LM and SIBO was statistically significant (P < 0.001). Seventy-nine of 86 pts (91.86%) showed normal OCTT, while OCTT remained prolonged but shorter in the remaining 7 pts (8.14%). SIBO was eradicated in all pts completing the study, while a new lactulose H₂-BT showed persistence of SIBO in one pt with recurrence of symptomatic diverticular disease. Forty-seven of 59 pts (79.66%) had a normal lactose H₂-BT (P < 0.002), while 12 of 59 pts (20.34%) showed persistence of LM. LM disappeared in 46 of 49 pts (93.88%) concurrently with normalization of OCTT and eradication of SIBO (P < 0.002); it also disappeared in 1 of 3 pts (33.33%) previously affected by delayed OCTT (without SIBO) and LM concurrently with normalization of OCTT. On the contrary, it persisted in all pts with normal OCTT and absence of SIBO. Moreover, it persisted also in the pt with recurrence of symptomatic diverticular disease and persistence of SIBO. In conclusion, most pts affected by symptomatic uncomplicated diverticular disease of the colon showed LM, and in more than 70% of cases it disappeared after successful treatment of the colonic disease.     

Peripheral nerve concentrations of glucose,fructose, sorbitol and myoinositol in diabetic and non-diabetic patients

Summary Glucose, fructose, sorbitol and myoinositol concentrations were measured in biopsies of peripheral nerve obtained at above-knee or below-knee amputation. In diabetic patients nerve glucose (median [range]) (5.09 [1.62–12.82] vs 3.12 [1.81–4.01]) p<0.001, fructose (0.245 [0.060–1.280] vs 0.150 [0.053–0.385]) p<0.05, and sorbitol (0.028 [0.012–0.496] vs 0.016 [0.007–0.059] p<0.02, mol/g wet weight) were significantly higher than in non-diabetic patients. No significant difference was found in myoinositol concentration (1.95 [1.00–3.55] vs 2.09 [1.27–5.40] mol/g wet weight). Concentrations differed markedly from previously reported values in human nerve obtained at post-mortem.     

Effects of ingested fructose and infused glucagon on endogenous glucose production in obese NIDDM patients,obese non-diabetic subjects,and healthy subjects

Summary Increased endogenous glucose production (EGP) and gluconeogenesis contribute to the pathogenesis of hyperglycaemia in non-insulin-dependent diabetes mellitus (NIDDM). In healthy subjects, however, EGP remains constant during administration of gluconeogenic precursors. This study was performed in order to determine whether administration of fructose increases EGP in obese NIDDM patients and obese non-diabetic subjects. Eight young healthy lean subjects, eight middle-aged obese NIDDM patients and seven middle-aged obese non-diabetic subjects were studied during hourly ingestion of ¹³C fructose (0.3 g · kg fat free mass^–1 · h^–1) for 3 h. Fructose failed to increase EGP (measured with 6,6 ²H glucose) in NIDDM (17.7±1.9 mol · kg fat free mass^–1 · min^–1 basal vs 15.9±0.9 after fructose), in obese non-diabetic subjects (12.1±0.5 basal vs 13.1±0.5 after fructose) and in lean healthy subjects (13.3±0.5 basal vs 13.8±0.6 after fructose) although ¹³C glucose synthesis contributed 73.2% of EGP in lean subjects, 62.6% in obese non-diabetic subjects, and 52.8% in obese NIDDM patients. Since glucagon may play an important role in the development of hyperglycaemia in NIDDM, healthy subjects were also studied during ¹³C fructose ingestion + hyperglucagonaemia (232±9 ng/l) and during hyperglucagonaemia alone. EGP increased by 19.8% with ingestion of fructose + glucagon (p<0.05) but remained unchanged during administration of fructose or glucagon alone. The plasma ¹³C glucose enrichment was identical after fructose ingestion both with and without glucagon, indicating that the contribution of fructose gluconeogenesis to the glucose 6-phosphate pool was identical in these two conditions. We concluded that during fructose administration: 1) gluconeogenesis is increased, but EGP remains constant in NIDDM, obese non-diabetic, and lean individuals; 2) in lean individuals, both an increased glucagonaemia and an enhanced supply of gluconeogenic precursors are required to increase EGP; this increase in EGP occurs without changes in the relative proportion of glucose 6-phosphate production from fructose and from other sources (i. e. glycogenolysis + gluconeogenesis from non-fructose precursors).Abbreviations EGP Endogenous glucose production - CHO carbohydrate - APE atom percent excess - GRd glucose rate of disappearance - FFM fat-free mass     

The sorbitol pathway: Effect of streptozotocin induced diabetes and the feeding of a sucrose-rich diet on glucose,sorbitol and fructose in the retina,blood and liver of rats

Summary The sorbitol, fructose and glucose content of the retina, blood and liver from normal and streptozotocin diabetic rats fed either a starch- or sucroserich diet for 15 days has been determined. The sorbitol and fructose level in the retina was much higher than that in either the liver or blood and was significantly increased in diabetes on either diet. Such increases in the sorbitol concentration did not occur in either the liver or the blood during diabetes, and the possibility that the sorbitol pathway can play an important metabolic role in the diabetic retina has been discussed. The feeding of a sucroseas opposed to a starchrich diet did not significantly alter the concentrations of glucose, sorbitol or fructose in the normal rat retina but caused a marked elevation in the diabetic state.     

The Effect of Ingested Lactulose on Absorption of L-Rhamnose,D-Xylose,and 3-O-Methyl-D-Glucose in Subjects with Ileostomies

Jenkins AP, Menzies IS, Nukajam WS, Creamer B. The effect of ingested lactulose on absorption of L-rhamnose, D-xylose. and 3-O-methyl-D-glucose in subjects with ileostomies. Scand J Gastroenterol 1994;29:820-825.

Background: We have previously shown that small oral doses of poorly absorbed solute can significantly reduce absorption of test sugars in normal volunteers. To confirm these results and investigate the underlying mechanism, the effects of lactulose on absorption of three test sugars in subjects with ileostomies were studied. Methods: Ten fasted subjects with ileostomies ingested an isosmolar test solution containing 2.5g 3-O-methyl-D-glucose, 5.0g D-xylose, 1.0g L-rhamnose, and 50μCi ⁵¹Cr-labelied ethylenediaminetetraacetic acid together with a blue dye transit marker. Urine was collected for time periods of 0-5 h and 5-24 h, to measure excretion of absorbed sugars, and ileostomy effluent was saved from 0-5 h and from 5 h until blue dye transit marker was no longer present, to measure small-bowel output of unabsorbed sugars. After 1 week the test was repeated, including 5 g lactulose in the test solution. Results: Inclusion of lactulose in the test solution significantly reduced the 5 h and 24 h urine excretion of l -rhamnose and D-xylose but not that of 3-O-methyl-D-glucose and increased 0- to 5-h and total ileostomy output of L-rhamnose and D-xylose but not of 3-O-methyl-D-glucose. The presence of lactulose also reduced the time for first appearance of the blue dye transit marker in the effluent and increased effluent volume together with output of electrolyte. Conclusion: Poorly absorbed solute reduces intestinal absorption by retention of fluid and electrolyte, with subsequent intraluminal dilution and acceleration of transit.     

Sorbitol and myo-inositol levels and morphology of sural nerve in relation to peripheral nerve function and clinical neuropathy in men with diabetic, impaired, and normal glucose tolerance.

AIMS: Sorbitol and myo-inositol levels and morphology of sural nerve were compared with nerve function and clinical neuropathy in men with diabetic, impaired (IGT), and normal glucose tolerance. METHODS: After neurography of sural nerve and determinations of sensory thresholds for vibration, warm and cold on the foot, whole nerve sural nerve biopsy was performed in 10 men with Type 1 diabetes mellitus, 10 with IGT, and 10 with normal glucose tolerance. Polyol levels were assessed by gas-liquid chromatography/mass spectrometry. RESULTS: Sural nerve amplitudes were significantly lower and sorbitol levels significantly higher in diabetic patients (median (interquartile range)) (3.7 (3.5) microV and 643 (412) pmol/mg protein, respectively) both compared with IGT (11.3 (10.6)microV; P = 0.04 and 286 (83) pmol/mg protein; P = 0.0032, respectively) and normally glucose tolerant (10.0 (11.6); P = 0.0142 and 296 (250) pmol/mg protein; P = 0.0191, respectively) subjects. There were no differences in nerve morphology between the three groups. Nerve myo-inositol levels correlated, however, positively with cluster density (rs = 0.56; P = 0.0054). In diabetic and IGT subjects, sural nerve amplitudes (2.6 (3.8) vs. 12.1 (10.6) microV; P = 0.0246) and myelinated nerve fibre density (MNFD; 4,076 (1091) vs. 5,219 (668) nerve fibres/mm2; P = 0.0021) were significantly lower in nine subjects with clinical neuropathy than in 10 without. CONCLUSIONS: Nerve degeneration (i.e. MNFD) correlated with clinical neuropathy but not with glucose tolerance status whereas nerve myo-inositol levels positively correlated with signs of nerve regeneration (i.e. increased cluster density).     

Posttransplantation Engraftment and Safety of Cord Blood Transplantation with Grafts Containing Relatively Low Cell Doses in Adults

The cell dose of a graft is a critical determinant of hematopoietic recovery and survival following unrelated cord blood transplantation. Most studies have found that the minimum acceptable nucleated cell dose should be between 1.5 X 10(7) and 2.0 X 10(7) nucleated cells per kilogram of body weight to reduce the time to myeloid recovery and increase the probability of engraftment. For some patients who have indications for hematopoietic cell transplants and for whom no other graft source except cord blood is available, it is difficult to decide whether they can receive cord blood grafts containing lower cell doses. In our study, patients who received cord blood grafts containing 1.0 X 10(7) to 2.0 X 10(7) cells/kg (n = 7) exhibited slower neutrophil and platelet recoveries compared with patients who received grafts containing total nucleated cell doses of 2.0 X 10(7) cells/kg and above (n = 93); however, 4 of those low-cell-dose recipients survived with a longer follow-up. Based on these preliminary results, cord blood grafts containing less than 2.0 X 10(7) cells/kg may be useful for cases where no grafts with higher cell doses or other stem cell sources are available.     

Stimulation of Non-Sodium-Dependent Water, Electrolyte, and Glucose Transport in Rat Small Intestine by Gum Arabic

In experimental models of gastroenterological disease, the soluble fiber gum arabic (GA) acts as a proabsorptive adjuvant. This study investigated which specific transport pathway(s) are affected by GA. Rat jejunum was perfused under anesthesia with a standardized oral rehydration solution (ORS) containing d-glucose, with or without GA (2.5 g/liter). In some preparations either phloridizin, a competitive inhibitor of Na⁺-coupled d-glucose transport, or phloretin, an inhibitor of basolateral glucose transport, were added to the ORS, with or without GA. Diffusion and paracellular transport changes due to GA were evaluated with l-glucose and [¹⁴C]polyethlyene glycol 4000 (PEG). GA partially reversed water, Na⁺, and d-glucose absorption inhibition induced by phloridzin and normalized water and Na⁺ absorption in the presence of phloretin. GA also increased absorption of water, Na⁺, and PEG from an l-glucose ORS. The data suggest that GA does not act via Na⁺ dependent mechanism(s), but stimulates transcellular and/or transjunctional transport pathways; therefore GA may be useful to increase absorption of solutes transported by diffusion.     

Is Hyperinsulinaemia a Central Characteristic of a Chronic Cardiovascular Risk Factor Clustering Syndrome? Mixed Findings in Asian Indian,Creole and Chinese Mauritians

The aim of the study was to investigate whether the constellation of cardiovascular disease risk factors, described as Insulin Resistance Syndrome, exists in the multi-ethnic population of Mauritius, and to assess whether hyperinsulinaemia is the key feature of this syndrome. A sample of 5080 Mauritian subjects (aged 25–74 years) was examined in a non-communicable diseases survey in 1987. Survey procedure included an oral glucose tolerance test, and anthropometric, blood pressure, plasma lipids and serum insulin measurements. Abnormal glucose tolerance (diabetes and impaired glucose tolerance), general obesity, upper-body obesity, hypertension, low HDL-cholesterol, and hypertriglyceridaemia were defined as risk factor conditions. Mean values for a series of risk factor variables were compared between reference subjects (no risk factors) and those with a risk factor condition (either one condition only, or in combination with one or more others). Prevalence estimates for each risk factor condition in combination with three or more other conditions were three to four times greater than expected by chance, and levels of risk factors for subjects with more than one risk factor condition were further away from the reference levels than for those with just one condition. Fasting and 2-h serum insulin levels were elevated for each condition when in combination with others, or to a lesser extent when isolated. However, this was not the case for isolated hypertension where insulin levels were not elevated. When adjusted for age, sex, and body mass index, insulin levels were only significantly elevated in subjects with upper-body obesity if in association with general obesity. A clustering of cardiovascular risk factors was therefore found in Mauritius. However, insulin levels although high for most conditions were not high in hypertension.     

Low subcutaneous degradation and slow absorption of insulin in insulin-dependent diabetic patients during continuous subcutaneous insulin infusion at basal rate

Summary As information on the absorption kinetics and local degradation of infused insulin is relevant to programming strategies for continuous subcutaneous insulin infusion, we examined the time relationship of systemic insulin appearance and quantitated subcutaneous degradation during a near-basal rate of continuous subcutaneous insulin infusion in five insulin-dependent diabetic patients. Plasma free insulin was monitored for 8 h during and 3 h after a subcutaneous (abdominal wall) infusion of neutral insulin at 2.4 U/h. An identical intravenous infusion (2–4 h) was given on a separate occasion. Plateau levels of free insulin were not significantly different during the subcutaneous (37±8 mU/l) and intravenous (40±7 mU/l) infusions. Fitting of the free insulin data to our two-pool model of the subcutaneous space gave a mean estimate of 9.2 units insulin (= 3.8 h infusion) for the subcutaneous depot after 8 h. Model estimates of systemic insulin appearance, as a percentage of subcutaneous infusion rate, were 59% and 93% after 4 and 8 h respectively, and 76% 2 h after cessation of infusion. In insulin-dependent diabetic patients subcutaneous degradation of infused insulin is negligible but local accumulation in the subcutaneous space is considerable. The delay in absorption has important clinical implications for interruption and resumption of continuous subcutaneous insulin infusion and also for programming of variable basal rates.     

Assessment of the “Second Day” Exercise Effect on Glycemic Control,Insulin Requirements,and CHO Intake in Type 1 Diabetes Adults

Background:Glucose control during consecutive days of aerobic exercise has not been well studied. We assessed glycemia, insulin requirements, and carbohydrate (CHO) needs during two consecutive days of prolonged cycling in type 1 diabetes (T1D) adults using sensor-augmented insulin pump therapy.Methods:Twenty adults with well-controlled T1D and six healthy adults (for comparison) were enrolled. Assessments were made during two consecutive days of cycling activities (30 miles per day). On day 1 (D1), basal rates were reduced 50% and CHO intake was guided by real-time continuous glucose monitoring (rtCGM) data to maintain a target range (70-180 mg/dL). On day 2 (D2), basal insulin infusion was stopped for the first hour of biking and resumed at a minimal rate during biking. Carbohydrate intake one hour before, during, and ten minutes after biking was recorded. Times within/below target range, glycemic variability, and mean glucose were calculated from rtCGM data.Results:Among 17 T1D participants who completed the study, mean glucose levels at the start of cycling were slightly lower on D2 vs D1: 138 ± 16 mg/dL and 122 ± 16, respectively, P = NS. Type 1 diabetes participants achieved near-normal glucose levels at the end of both cycling events; however, the reduction in glucose was most notable at one hour into the event on D2 vs D1. Carbohydrate intake was notably lower during D2 vs D1 with no difference in time <54 mg/dL (both P = NS).Conclusions:Type 1 diabetes individuals using rtCGM-augmented insulin pump therapy can safely engage in consecutive days of prolonged aerobic exercise by significantly reducing insulin dosages with no increase in CHO intake.     

The Experience of Older Adults in a Walking Program at Individual,Interpersonal, and Environmental Levels

Walking programs are advocated to mobilize sedentary older adults. Thus, the study of age-specific social ecological walking programs are needed in order to develop interventions that offer best chance for success. The purpose of this study was to analyze the experience of participating in a walking program at individual, interpersonal, and environmental levels in order to identify appropriate strategies for walking interventions to older adults. A 10-month walking program was implemented, three times a week with 19 older adults (mean age = 67,42 ± 2,48). The participants were submitted to a pre and post evaluation of functional fitness, physical activity patterns, and perceptions of their neighborhood environment. After the program, semi-structured interviews were conducted with 12 randomly selected participants. The results highlight the potential of this walking program by enhancing physical and mental health, creating supportive social networks, and a context of walking in nature which was crucial for the promotion of the active lifestyle and functional improvement of older adults participants.