A Definition of “Flare” in Low Back Pain: A Multiphase Process Involving Perspectives of Individuals With Low Back Pain and Expert Consensus

Low back pain (LBP) varies over time. Consumers, clinicians, and researchers use various terms to describe LBP fluctuations, such as episodes, recurrences and flares. Although “flare” is use commonly, there is no consensus on how it is defined. This study aimed to obtain consensus for a LBP flare definition using a mixed-method approach. Step 1 involved the derivation of a preliminary candidate flare definition based on thematic analysis of views of 130 consumers in consultation with an expert consumer writer. In step 2, a workshop was conducted to incorporate perspectives of 19 LBP experts into the preliminary flare definition, which resulted in 2 alternative LBP flare definitions. Step 3 refined the definition using a 2-round Delphi consensus with 50 experts in musculoskeletal conditions. The definition favored by experts was further tested with 16 individuals with LBP in step 4, using the definition in three scenarios. This multiphase study produced a definition of LBP flare that distinguishes it from other LBP fluctuations, represents consumers’ views, involves expert consensus, and is understandable by consumers in clinical and research contexts: “A flare-up is a worsening of your condition that lasts from hours to weeks that is difficult to tolerate and generally impacts your usual activities and/or emotions.”Perspective: A multiphase process, incorporating consumers’ views and expert consensus, produced a definition of LBP flare that distinguishes it from other LBP fluctuations.     

The Effects of an 8-Week Stabilization Exercise Program on Lumbar Multifidus Muscle Thickness and Activation as Measured With Ultrasound Imaging in Patients With Low Back Pain: An Exploratory Study

Background

Lumbar stabilization exercise programs (LSEP) produce positive effects on clinical outcomes, but the underlying mechanisms remain relatively unexplored. Psychological and neuromuscular mechanisms can be involved, such as a better activation of the lumbar multifidus, which represents one possibility.

Is the Fear Avoidance Model Associated With the Reduced Level of Aerobic Fitness in Patients With Chronic Low Back Pain?

Smeets RJ, van Geel KD, Verbunt JA. Is the fear avoidance model associated with the reduced level of aerobic fitness in patients with chronic low back pain?

Objectives

To compare aerobic fitness of patients with chronic low back pain (CLBP) against healthy controls and to assess whether variables of the fear avoidance model are associated with loss of aerobic fitness.

Design

A case-comparison study.

Setting

Rehabilitation centers.

Participants

Patients with CLBP (n=223), and normative data from healthy subjects (n=18,082).

Interventions

Not applicable.

Main Outcome Measures

Maximal oxygen uptake (V?o₂max) was estimated on the basis of a modified submaximal Åstrand bicycle test performed by patients with CLBP (observed level of aerobic fitness) and compared with the normative data of healthy controls matched for age, sex, and level of sport activity (expected level of aerobic fitness). Pain (visual analog scale); disability (Roland Disability Questionnaire); pain-related fear (Tampa Scale for Kinesiophobia); depression (Beck Depression Inventory); catastrophizing (Pain Catastrophizing Scale); and the level of activity during sport, work/household, and leisure time (Baecke Physical Activity Questionnaire) were assessed. Multiple linear regression analysis was performed with the difference of the observed and expected level of aerobic fitness as dependent variable and putative influential factors including those of the fear avoidance model as independent variables.

Results

V?o₂max could be calculated in 175 (78%) of the patients. Both men and women with CLBP had significant lower V?o₂max than expected (10.3mL/kg lean body mass (LBM)×min⁻¹ and 6.5mL/kg LBM×min⁻¹, respectively; P<.001). The levels of activity during leisure time and work/household were significantly associated with this reduced level of aerobic fitness. However, the variables of the fear avoidance model were not.

Conclusions

Most patients with CLBP-associated disability have a lower level of aerobic fitness, but this is not associated with fear avoidance.     

Factors Associated With Adolescent Chronic Non-Specific Pain,Chronic Multisite Pain,and Chronic Pain With High Disability: The Young–HUNT Study 2008

The aim of this study was to assess the association of chronic pain with different lifestyle factors and psychological symptoms in a large, unselected adolescent population. Pain was evaluated as chronic non-specific pain, chronic multisite pain, and in additional analyses, chronic pain with high disability. The study was performed during 2006 to 2008 in Nord-Trøndelag County, Norway. Adolescents aged 13 to 18 years were invited to participate. The response rate was 78%. The final study population consisted of 7,373. Sedentary behavior and pain were associated only in girls. In both sexes, overweight and obesity were associated with increased odds of pain. Whereas both smoking and alcohol intoxication showed strong associations with pain, the associations were attenuated after adjustments for psychosocial factors. Symptoms of anxiety and depression showed the strongest associations with pain (odds ratio 4.1 in girls and 3.7 in boys). The odds of pain increased gradually by number of unfavorable lifestyle factors reported. This study revealed consistent associations between lifestyle factors, anxiety and depression, and chronic pain, including multisite pain and pain with high disability. The consistency across the different pain categories suggests common underlying explanatory mechanisms, and despite the cross-sectional design, the study indicates several modifiable targets in the management of adolescent chronic pain.PerspectiveThis study showed a clear and consistent relation between different lifestyle factors, anxiety and depression, and the pain categories chronic non-specific pain, multisite pain, and also pain with high disability. Independent of causality, it underlines the importance of a broad perspective when studying, preventing, and treating chronic pain in adolescents.     

Association of Patterns of Moderate-to-Vigorous Physical Activity Bouts With Pain,Physical Fatigue,and Disease Severity in Women With Fibromyalgia: the al-Ándalus Project

ObjectivesTo examine the associations of non-bouted moderate-to-vigorous physical activity (MVPA) and patterns of MVPA in bouts ≥10 minutes with pain, physical fatigue, and disease severity in women with fibromyalgia, and test whether these associations are independent of sedentary time (ST) and physical fitness (PF).DesignCross-sectional study carried out from November 2011 to January 2013.SettingUniversity facilities and fibromyalgia associations.ParticipantsWomen with fibromyalgia (N=439; 51.3±7.6y).InterventionsNot applicable.Main Outcome MeasuresST and MVPA were measured with triaxial accelerometry, and PF with the Senior Fitness test battery. We assessed pain, physical fatigue and disease severity with diverse questionnaires.ResultsTotal time in non-bouted MVPA only was independently associated with lower physical fatigue (B=-0.012; P=.010) and disease severity (B=-0.068; P=.007) in women with fibromyalgia, regardless of PF but not of ST. Patterns of bouted MVPA were overall associated with symptoms independently of ST or PF. The strongest regressor was the maximum time in MVPA bout (min/bout), which was consistently and independently associated with pain, physical fatigue and disease severity after controlling for ST or PF (all, P≤.002). Patients meeting bouted physical activity guidelines displayed lower disease severity than those not meeting guidelines (bouted or non-bouted) and those meeting non-bouted physical activity guidelines (all, P≤.008).ConclusionsPatterns of MVPA performed in bouts ≥10 minutes were overall consistently and independently associated with core symptoms (pain and fatigue) in fibromyalgia and the overall disease severity, regardless of ST or PF. The results suggest that longer bouts of continuous MVPA are associated with better symptoms profile in this population, which needs to be corroborated in longitudinal research.     

Responsiveness and Minimally Important Differences for 4 Patient-Reported Outcomes Measurement Information System Short Forms: Physical Function,Pain Interference,Depression, and Anxiety in Knee Osteoarthritis

Patient-Reported Outcomes Measurement Information System (PROMIS) instruments can provide valid, interpretable measures of health status among adults with osteoarthritis (OA). However, their ability to detect meaningful change over time is unknown. We evaluated the responsiveness and minimally important differences (MIDs) for 4 PROMIS Short Forms: Physical Function, Pain Interference, Depression, and Anxiety. We analyzed adults with symptomatic knee OA from our randomized trial comparing Tai Chi and physical therapy. Using baseline and 12-week scores, responsiveness was evaluated according to consensus standards by testing 6 a priori hypotheses of the correlations between PROMIS and legacy change scores. Responsiveness was considered high if ≥5 hypotheses were confirmed, and moderate if 3 or 4 were confirmed. MIDs were evaluated according to prospective change for people achieving previously-established MID on legacy comparators. The lowest and highest MIDs meeting a priori quality criteria formed a MID range for each PROMIS Short Form. Among 165 predominantly female (70%) and white (57%) participants, mean age was 61 years and body mass index was 33. PROMIS Physical Function had 5 confirmed hypotheses and Pain Interference, Depression, and Anxiety had 3 or 4. MID ranges were: Depression = 3.0 to 3.1; Anxiety = 2.3 to 3.4; Physical Function = 1.9 to 2.2; and Pain Interference = 2.35 to 2.4. PROMIS Physical Function has high responsiveness, and Depression, Anxiety, and Pain Interference have moderate responsiveness among adults with knee OA. We established the first MIDs for PROMIS in this population, and provided an important standard of reference to better apply or interpret PROMIS in future trials or clinical practice.

Exploration of the Nociception Level (NOL™) Index for Pain Assessment during Endotracheal Suctioning in Mechanically Ventilated Patients in the Intensive Care Unit: An Observational and Feasibility Study

BackgroundMany patients in the intensive care unit (ICU) suffer from pain and are non-communicative. Therefore, alternative pain measures are necessary. Although behavioral pain measures are available, physiological measures are lacking. The Nociception Level index (NOL™) provides a value from combination of multiple physiological parameters to measure pain and its use in the ICU is new.AimTo explore the use of a multiple physiological parameter measure for pain assessment, the NOL™ index, in mechanically ventilated patients able to self-report pain in the ICU.MethodsA prospective cohort study was performed. Data were collected before, during, and 15 minutes after a non-nociceptive procedure (noninvasive blood pressure using cuff inflation) and a nociceptive procedure (endotracheal suctioning). NOL index, 0 to 10 pain intensity, and Critical-Care Pain Observation Tool (CPOT) scores were also obtained. Data were analyzed using Friedman and Mann-Whitney tests. Feasibility of study procedures was described.ResultsOut of 28 patients who consented, 17 remained eligible and data were analyzed for 15. Technical issues prevented obtaining a NOL signal in 2 patients. NOL values were higher during endotracheal suctioning (median = 41.6) compared with before (median = 11.2) and after the procedure (median = 11.8) and compared with cuff inflation (median = 15.1; Friedman test, p < .001). NOL values were associated with pain intensity and CPOT scores (Mann-Whitney tests, p < .05).ConclusionsThe study procedures with the NOL were found feasible; NOL values could discriminate between nociceptive and non-nociceptive procedures, and values were associated with reference pain measures. Further NOL testing is required in other ICU patient groups and procedures.     

Immediate Effects of Core Stabilization Exercise on β-Endorphin and Cortisol Levels Among Patients With Chronic Nonspecific Low Back Pain: A Randomized Crossover Design

Objective

The main objective of the study was to measure the levels of plasma β-endorphin (PB) and plasma cortisol (PC) under lumbar core stabilization exercise (LCSE), placebo and control conditions in patients with chronic nonspecific low back pain.

Prevalence and Predictors of Prehospital Pain Assessment and Analgesic Use in Military Trauma Patients, 2010–2013

Introduction: Pain is the most common symptom in patients presenting for prehospital (PH) care. Research in civilian emergency medical systems has shown wide variability in PH pain assessment and analgesic practices, yet a minimal amount is known about pain assessment and analgesic intervention practices in the military, particularly when PH care is delivered in a combat zone. Objective: To describe prehospital (PH) pain care practices for U.S. military personnel injured in Iraq and Afghanistan 2010–2013 and explore potential relationships to explain variation. Methods: An exploratory retrospective, cross-sectional study of Department of Defense Trauma Registry data from 2010 to 2013 was performed. Demographic, clinical, or health system variables for associations with three outcomes: 1) pain assessment documentation; 2) pain severity (0–10 scale); and 3) analgesic administration (yes/no). Including only variables with significant associations, backward stepwise regression was used to develop explanatory models for each outcome. Results: Patient records (n = 3,317) were evaluated for documentation of PH pain assessment and analgesic administration. The prevalence of PH pain score documentation was 37.8% (n = 1,253). Overall, the proportion of records with PH pain scores increased over time: 19.8% (2010), 35.1% (2011), 58.2% (2012), and 62.2% (2013). Severity of pain scores ranged 0–10; mean = 5.5 (SD = 3.1); median = 6 (IQR = 3–8). Analgesics were reported for 50.8% (n = 1,684), of whom 38.3% had a pain severity score documented. The pain assessment documentation model included any documented vital signs, injury year, and mechanism of injury and explained 19.3% of the variance in documentation. The pain severity model included vital signs and injury severity score (ISS) and explained 5.0% of the variance in severity. The analgesic model included any vital signs, pain severity, trauma type, mechanism of injury, ISS, and year. Conclusions: Pain assessment and treatment documentation improved each year, but remain suboptimal. Available data yielded poor prediction of the outcomes of interest, emphasizing the importance of individual assessment. Analgesic effectiveness could not be evaluated.     

Physical Activity–Based Interventions Using Electronic Feedback May Be Ineffective in Reducing Pain and Disability in Patients With Chronic Musculoskeletal Pain: A Systematic Review With Meta-Analysis

Objective

To investigate the effectiveness of physical activity–based interventions using electronic feedback in reducing pain and disability compared to minimal or no interventions in patients with chronic musculoskeletal pain.

PAINSTORIES – Exploring the Temporal Developments in the Challenges,Barriers, and Self-Management Needs of Adolescents with Longstanding Knee Pain: A Qualitative,Retrospective Interview Study with Young Adults Experiencing Knee Pain Since Adolescence

Patient education is essential to enable rehabilitation and self-management of longstanding knee pain in adolescents. Currently, a lack of insights into the socio-cognitive processes governing adolescents’ self-management remains an obstacle for enhancing treatment efficacy. This study developed a conceptual model for integrating adolescents’ challenges and barriers into future treatments. We conducted semi-structured retrospective interviews with 14 young adults (age 21–25 years) with knee pain since adolescence (9 years mean duration). Temporal developments in participants’ knee pain were captured through a memorization exercise. Data was analyzed via the General Inductive Approach. Themes were organized into a matrix, extracting a conceptual model, which was tested with eight new participants. The analysis identified seven themes. Further interpretation, via the matrix, organized these within a four-stage trajectory of; gaining awareness, knowledgeability, contextual application and reconceptualization, each with different challenges and dilemmas, participants had to overcome to progress their self-management. Testing the conceptual model, confirmed stages and highlighted acceptance as key to overcoming barriers. The study described adolescents’ integration of self-management as proximal and inquiry-based, with acceptance, driving increasingly complex management behaviors. We hypothesize future interventions may benefit from exploring supporting adolescents’ inquiries into their knee pain at different stages of the trajectory.PerspectiveThis study presents a conceptual model and vocabulary for optimizing patient education concepts, to target the challenges, barriers and needs of adolescents with knee pain at different stages of their mastery journey. We believe our findings may inform reflections among clinicians and researchers, and development of more effective education interventions.     

Outcomes of Acute and Chronic Patients With Magnetic Resonance Imaging–Confirmed Symptomatic Lumbar Disc Herniations Receiving High-Velocity,Low-Amplitude,Spinal Manipulative Therapy: A Prospective Observational Cohort Study With One-Year Follow-Up

Objective

The purposes of this study were to evaluate patients with low-back pain (LBP) and leg pain due to magnetic resonance imaging–confirmed disc herniation who are treated with high-velocity, low-amplitude spinal manipulation in terms of their short-, medium-, and long-term outcomes of self-reported global impression of change and pain levels at various time points up to 1 year and to determine if outcomes differ between acute and chronic patients using a prospective, cohort design.

Methods

This prospective cohort outcomes study includes 148 patients (between ages of 18 and 65 years) with LBP, leg pain, and physical examination abnormalities with concordant lumbar disc herniations. Baseline numerical rating scale (NRS) data for LBP, leg pain, and the Oswestry questionnaire were obtained. The specific lumbar spinal manipulation was dependent upon whether the disc herniation was intraforaminal or paramedian as seen on the magnetic resonance images and was performed by a doctor of chiropractic. Outcomes included the patient’s global impression of change scale for overall improvement, the NRS for LBP, leg pain, and the Oswestry questionnaire at 2 weeks, 1, 3, and 6 months, and 1 year after the first treatment. The proportion of patients reporting “improvement” on the patient’s global impression of change scale was calculated for all patients and acute vs chronic patients. Pretreatment and posttreatment NRS scores were compared using the paired t test. Baseline and follow-up Oswestry scores were compared using the Wilcoxon test. Numerical rating scale and Oswestry scores for acute vs chronic patients were compared using the unpaired t test for NRS scores and the Mann-Whitney U test for Oswestry scores. Logistic regression analysis compared baseline variables with “improvement.”

Results

Significant improvement for all outcomes at all time points was reported (P < .0001). At 3 months, 90.5% of patients were “improved” with 88.0% “improved” at 1 year. Although acute patients improved faster by 3 months, 81.8% of chronic patients reported “improvement” with 89.2% “improved” at 1 year. There were no adverse events reported.

Conclusions

A large percentage of acute and importantly chronic lumbar disc herniation patients treated with chiropractic spinal manipulation reported clinically relevant improvement.     

Correlations Between Individuals’ Characteristics and Spinal Stiffness in Individuals With and Without Back Pain: A Combined Analysis of Multiple Data Sets

Objective

The purpose of this study was to describe the correlations between individual characteristics and spinal stiffness as measured with different spinal stiffness measurement devices in individuals with and without back pain.

Investigation of the Phenomenon of Coronal–Sagittal Curvature Coupling on Curve Progression: An Exploratory Study using 3-D Ultrasound

A 3-D ultrasound system was determined to provide reliable and valid results for scoliosis assessment in the coronal and sagittal planes. The objective of this study was to investigate whether 3-D ultrasound can detect coronal–sagittal coupling and to study its potential effect on curve progression in patients with adolescence idiopathic scoliosis (AIS) as per the traditional Cobb angle classification. Radiographic and ultrasonic coronal and sagittal curvatures of 126 patients with AIS were evaluated. Thoracic kyphosis (TK) and lumbar lordosis (LL) with different coronal deformity were compared correspondingly based on either main thoracic or (thoraco)lumbar curve groups. The TK and LL of patients with single curves were also compared with study the curve effect on sagittal curvatures. A prospective cohort of 51 patients were followed for an average of 23 months for preliminary progression investigation. TKs in patients with larger main thoracic Cobb angles was significantly smaller than those with smaller main thoracic Cobb angles, judging by the results obtained from ultrasound and X-ray. The TKs of patients with only single right main thoracic curves were significantly smaller than those of patients with only single left (thoraco)lumbar curves. In addition, patients with progressive curves were observed to be relative hypokyphotic during early visits.     

Pharmacokinetics and Pharmacodynamics of Subcutaneous Recombinant Parathyroid Hormone (1–84) in Patients With Hypoparathyroidism: An Open-Label,Single-Dose,Phase I Study

Background

Impaired mineral homeostasis affecting calcium, phosphate, and magnesium is a result of parathyroid hormone (PTH) deficiency in hypoparathyroidism. The current standard of treatment with active vitamin D and oral calcium does not control levels of these major minerals. Recombinant full-length human PTH 1–84 (rhPTH[1–84]) is being developed for the treatment of hypoparathyroidism.

Objective

The goal of this study was to investigate the pharmacokinetics and pharmacodynamics of a single subcutaneous injection of rhPTH(1–84) in patients with hypoparathyroidism.

Methods

This was an open-label, dose-escalating study of single subcutaneous administration of 50 µg and then 100 µg of rhPTH(1–84). Enrolled patients (age range, 25–85 years) had ≥12 months of diagnosed hypoparathyroidism defined according to biochemical evidence of hypocalcemia with concomitant low-serum intact PTH and were taking doses ≥1000 mg/d of oral calcium and ≥0.25 µg/d of active vitamin D (oral calcitriol). The patient’s prescribed dose of calcitriol was taken the day preceding but not on the day of or during the 24 hours after rhPTH(1–84) administration. Each patient received a single 50-µg rhPTH(1–84) dose, had at least a 7-day washout interval, and then received a single 100-µg rhPTH(1–84) dose. The following parameters were assessed: plasma PTH; serum and urine total calcium, magnesium, phosphate, and creatinine; and urine cyclic adenosine monophosphate.

Results

After administration of rhPTH(1–84) 50 µg (n = 6) and 100 µg (n = 7), the approximate t_½ was 2.5 to 3 hours. Plasma PTH levels increased rapidly, then declined gradually back to predose levels at ~12 hours. The median AUC was similar with calcitriol and rhPTH(1–84) for serum 1,25-dihydroxyvitamin D (calcitriol, 123–227 pg · h/mL; rhPTH[1–84], 101–276 pg · h/mL), calcium (calcitriol, 3.3–3.7 mg · h/dL; rhPTH[1–84], 3.3–7.6 mg · h/dL), and magnesium (calcitriol, 0.7–0.9 mg · h/dL; rhPTH[1–84], 1.3–2.8 mg · h/dL). In contrast, the median AUC for phosphate was strongly negative with rhPTH(1–84) (calcitriol, −1.0 to 0.8 mg · h/dL; rhPTH[1–84], −21.3 to −26.5 mg · h/dL). Compared with calcitriol, rhPTH(1–84) 50 µg reduced 24-hour calcium excretion and calcium-to-creatinine ratios by 12% and 23%, respectively, and rhPTH(1–84) 100 µg reduced them by 26% and 27%. There was little overall impact on urine magnesium levels. Compared with calcitriol, rhPTH(1–84) 50 µg increased urinary phosphate excretion and phosphate-to-creatinine ratios by 53% and 54%, respectively, and rhPTH(1–84) 100 µg increased them by 45% and 42%. Urine cyclic adenosine monophosphate–to–creatinine ratio increased with rhPTH(1–84) by 2.3-fold (50 µg) and 4.4-fold (100 µg) compared with calcitriol.

Conclusions

PTH replacement therapy with rhPTH(1–84) regulated mineral homeostasis of calcium, magnesium, phosphate, and vitamin D metabolism toward normal in these study patients with hypoparathyroidism.     

Symptomatic Magnetic Resonance Imaging–Confirmed Lumbar Disk Herniation Patients: A Comparative Effectiveness Prospective Observational Study of 2 Age- and Sex-Matched Cohorts Treated With Either High-Velocity,Low-Amplitude Spinal Manipulative Therapy or Imaging-Guided Lumbar Nerve Root Injections

ObjectivesThe purpose of this study was to compare self-reported pain and “improvement” of patients with symptomatic, magnetic resonance imaging–confirmed, lumbar disk herniations treated with either high-velocity, low-amplitude spinal manipulative therapy (SMT) or nerve root injections (NRI).MethodsThis prospective cohort comparative effectiveness study included 102 age- and sex-matched patients treated with either NRI or SMT. Numerical rating scale (NRS) pain data were collected before treatment. One month after treatment, current NRS pain levels and overall improvement assessed using the Patient Global Impression of Change scale were recorded. The proportion of patients, “improved” or “worse,” was calculated for each treatment. Comparison of pretreatment and 1-month NRS scores used the paired t test. Numerical rating scale and NRS change scores for the 2 groups were compared using the unpaired t test. The groups were also compared for “improvement” using the χ² test. Odds ratios with 95% confidence intervals were calculated. Average direct procedure costs for each treatment were calculated.ResultsNo significant differences for self-reported pain or improvement were found between the 2 groups. “Improvement” was reported in 76.5% of SMT patients and in 62.7% of the NRI group. Both groups reported significantly reduced NRS scores at 1 month (P = .0001). Average cost for treatment with SMT was Swiss Francs 533.77 (US $558.75) and Swiss Francs 697 (US $729.61) for NRI.ConclusionsMost SMT and NRI patients with radicular low back pain and magnetic resonance imaging–confirmed disk herniation matching symptomatic presentation reported significant and clinically relevant reduction in self-reported pain level and increased global perception of improvement. There were no significant differences in outcomes between NRI and SMT. When considering direct procedure costs, the average cost of SMT was slightly less expensive.     

Low Carbohydrate–Diet Scores and Long-term Risk of Type 2 Diabetes Among Women With a History of Gestational Diabetes Mellitus: A Prospective Cohort Study

OBJECTIVE

Low-carbohydrate diets (LCDs) may improve short-term glycemic control in patients with gestational diabetes mellitus (GDM), but the long-term effect on progression from GDM to type 2 diabetes mellitus (T2DM) is unknown. We aimed to examine the long-term risk of T2DM in association with a low-carbohydrate dietary pattern among women with a history of GDM.

RESEARCH DESIGN AND METHODS

Overall, 4,502 women with a history of GDM from the Nurses'' Health Study II (NHSII) cohort, as part of the Diabetes & Women’s Health (DWH) study, were followed up from 1991 to 2011. Overall, animal, or vegetable LCD scores, which represent adherence to different low-carbohydrate dietary patterns, were calculated using diet intake information assessed every 4 years since 1991 by validated food-frequency questionnaires. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

We documented 722 incident cases of T2DM during 68,897 person-years of observation. The multivariable-adjusted HRs (95% CIs) of T2DM, comparing the highest with lowest quintiles, were 1.36 (1.04–1.78) for overall LCD score (P = 0.003 for trend), 1.40 (1.06–1.84) for animal LCD score (P = 0.004 for trend), and 1.19 (0.91–1.55) for vegetable LCD score (P = 0.50 for trend).

CONCLUSIONS

Among women with a history of GDM, a low-carbohydrate dietary pattern, particularly with high protein and fat intake mainly from animal-source foods, is associated with higher T2DM risk, whereas a low-carbohydrate dietary pattern with high protein and fat intake from plant-source foods is not significantly associated with risk of T2DM.