We compared the effects of two diets on glycated hemoglobin (HbA1c) and other health-related outcomes in overweight or obese adults with type 2 diabetes or prediabetes (HbA1c>6%). We randomized participants to either a medium carbohydrate, low fat, calorie-restricted, carbohydrate counting diet (MCCR) consistent with guidelines from the American Diabetes Association (n = 18) or a very low carbohydrate, high fat, non calorie-restricted diet whose goal was to induce nutritional ketosis (LCK, n = 16). We excluded participants receiving insulin; 74% were taking oral diabetes medications. Groups met for 13 sessions over 3 months and were taught diet information and psychological skills to promote behavior change and maintenance. At 3 months, mean HbA1c level was unchanged from baseline in the MCCR diet group, while it decreased 0.6% in the LCK group; there was a significant between group difference in HbA1c change favoring the LCK group (-0.6%, 95% CI, -1.1% to -0.03%, p = 0.04). Forty-four percent of the LCK group discontinued one or more diabetes medications, compared to 11% of the MCCR group (p = 0.03); 31% discontinued sulfonylureas in the LCK group, compared to 5% in the MCCR group (p = 0.05). The LCK group lost 5.5 kg vs. 2.6 kg lost in MCCR group (p = 0.09). Our results suggest that a very low carbohydrate diet coupled with skills to promote behavior change may improve glycemic control in type 2 diabetes while allowing decreases in diabetes medications. This clinical trial was registered with ClinicalTrials.gov, number NCT01713764.

Why do some individuals become dissatisfied with their marriages when levels of negative emotion are high and levels of positive emotions are low, whereas others remain unaffected? Using data from a 13-year longitudinal study of middle-aged and older adults in long-term marriages, we examined whether the 5-HTTLPR polymorphism in the serotonin transporter gene moderates the association between negative and positive emotional behavior (objectively measured during marital conflict) and changes in marital satisfaction over time. For individuals with two short alleles of 5-HTTLPR, higher negative and lower positive emotional behavior at Time 1 predicted declines in marital satisfaction over time (even after controlling for depression and other covariates). For individuals with one or two long alleles, emotional behavior did not predict changes in marital satisfaction. We also found evidence for a crossover interaction (individuals with two short alleles of 5-HTTLPR and low levels of negative or high levels of positive emotion had the highest levels of marital satisfaction). These findings provide the first evidence of a specific genetic polymorphism that moderates the association between emotional behavior and changes in marital satisfaction over time and are consistent with increasing evidence that the short allele of this polymorphism serves as a susceptibility factor that amplifies sensitivity to both negative and positive emotional influences.

The present research examined the effect of the 5-HTTLPR polymorphism in the serotonin transporter gene on objectively coded positive emotional expressions (i.e., laughing and smiling behavior objectively coded using the Facial Action Coding System). Three studies with independent samples of participants were conducted. Study 1 examined young adults watching still cartoons. Study 2 examined young, middle-aged, and older adults watching a thematically ambiguous yet subtly amusing film clip. Study 3 examined middle-aged and older spouses discussing an area of marital conflict (that typically produces both positive and negative emotion). Aggregating data across studies, results showed that the short allele of 5-HTTLPR predicted heightened positive emotional expressions. Results remained stable when controlling for age, gender, ethnicity, and depressive symptoms. These findings are consistent with the notion that the short allele of 5-HTTLPR functions as an emotion amplifier, which may confer heightened susceptibility to environmental conditions.

Background

Adults with type 2 diabetes may experience health benefits, including glycemic control and weight loss, from following a very low-carbohydrate, ketogenic (VLC) diet. However, it is unclear which ancillary strategies may enhance these effects.

Objective

This pilot study aims to estimate the effect sizes of 3 intervention enhancement strategies (text messages, gifts, and breath vs urine ketone self-monitoring) that may improve outcomes of a 12-month web-based ad libitum VLC diet and lifestyle intervention for adults with type 2 diabetes. The primary intervention also included other components to improve adherence and well-being, including positive affect and mindfulness as well as coaching.

Methods

Overweight or obese adults (n=44; BMI 25-45 kg/m²) with type 2 diabetes (glycated hemoglobin [HbA_1c] ≥6.5%), who had been prescribed either no glucose-lowering medications or metformin alone, participated in a 12-month web-based intervention. Using a 2×2×2 randomized factorial design, we compared 3 enhancement strategies: (1) near-daily text messages about the intervention's recommended behaviors (texts n=22 vs no texts n=22), (2) mailed gifts of diet-relevant foods and cookbooks (6 rounds of mailed gifts n=21 vs no gifts n=23), and (3) urine- or breath-based ketone self-monitoring (urine n=21 vs breath n=23). We assessed HbA_1c and weight at baseline and at 4, 8, and 12 months. We evaluated whether each strategy exerted a differential impact on HbA_1c and weight at 12 months against an a priori threshold of Cohen d of 0.5 or greater.

Results

We retained 73% (32/44) of the participants at 12 months. The intervention, across all conditions, led to improvements in glucose control and reductions in body weight at the 12-month follow-up. In intent-to-treat (ITT) analyses, the mean HbA_1c reduction was 1.0% (SD 1.6) and the mean weight reduction was 5.3% (SD 6.0), whereas among study completers, these reductions were 1.2% (SD 1.7) and 6.3% (SD 6.4), respectively, all with a P value of less than .001. In ITT analyses, no enhancement strategy met the effect size threshold. Considering only study completers, 2 strategies showed a differential effect size of at least a d value of 0.5 or greater.

Conclusions

Text messages, gifts of food and cookbooks, and urine-based ketone self-monitoring may potentially enhance the glycemic or weight loss benefits of a web-based VLC diet and lifestyle intervention for individuals with type 2 diabetes. Future research could investigate other enhancement strategies to help create even more effective solutions for the treatment of type 2 diabetes.

Trial registration

ClinicalTrials.gov NCT02676648; http://clinicaltrials.gov/ct2/show/NCT02676648.

What can a speech reveal about someone's state? We tested the idea that greater stress reactivity would relate to lower linguistic cognitive complexity while speaking. In Study 1, we tested whether heart rate and emotional stress reactivity to a stressful discussion would relate to lower linguistic complexity. In Studies 2 and 3, we tested whether a greater cortisol response to a standardized stressful task including a speech (Trier Social Stress Test) would be linked to speaking with less linguistic complexity during the task. We found evidence that measures of stress responsivity (emotional and physiological) and chronic stress are tied to variability in the cognitive complexity of speech. Taken together, these results provide evidence that our individual experiences of stress or "stress signatures"-how our body and mind react to stress both in the moment and over the longer term-are linked to how complex our speech under stress.

We compared the effects of two diets on glycated hemoglobin (HbA1c) and other health-related outcomes in overweight or obese adults with type 2 diabetes or prediabetes (HbA1c>6%). We randomized participants to either a medium carbohydrate, low fat, calorie-restricted, carbohydrate counting diet (MCCR) consistent with guidelines from the American Diabetes Association (n = 18) or a very low carbohydrate, high fat, non calorie-restricted diet whose goal was to induce nutritional ketosis (LCK, n = 16). We excluded participants receiving insulin; 74% were taking oral diabetes medications. Groups met for 13 sessions over 3 months and were taught diet information and psychological skills to promote behavior change and maintenance. At 3 months, mean HbA1c level was unchanged from baseline in the MCCR diet group, while it decreased 0.6% in the LCK group; there was a significant between group difference in HbA1c change favoring the LCK group (-0.6%, 95% CI, -1.1% to -0.03%, p = 0.04). Forty-four percent of the LCK group discontinued one or more diabetes medications, compared to 11% of the MCCR group (p = 0.03); 31% discontinued sulfonylureas in the LCK group, compared to 5% in the MCCR group (p = 0.05). The LCK group lost 5.5 kg vs. 2.6 kg lost in MCCR group (p = 0.09). Our results suggest that a very low carbohydrate diet coupled with skills to promote behavior change may improve glycemic control in type 2 diabetes while allowing decreases in diabetes medications. This clinical trial was registered with ClinicalTrials.gov, number NCT01713764.

Background

This manuscript describes the first two phases of pilot testing MARIGOLD, an online self-guided positive emotion skills intervention for adults with elevated depressive symptoms, along with enhancements to overcome retention and adherence problems reported in previous research.

Methods

Adults with elevated depressive symptoms were recruited online and assessed at baseline, post-intervention, 1- and 3-month follow-up. Phase 1 participants (n = 58) were randomized to MARIGOLD, daily emotion reporting, or waitlist. Phase 2 participants (n = 79) were randomized to MARIGOLD plus one enhancement: online discussion board (ODB), virtual badges (VB), or facilitator contact (FC). Post-intervention interviews assessed acceptability. Intention-to-treat analyses examined retention, adherence, and preliminary efficacy.

Results

In both phases, retention and adherence did not differ between groups. MARIGOLD skills were highly acceptable, but qualitative results indicate web-based features (e.g., log-in, ODB, VB) require refinement prior to larger testing. Neither phase demonstrated between-group differences in preliminary efficacy. In Phase 1 within-group analyses, MARIGOLD and emotion reporting control demonstrated a similar pattern of findings (stable depressive symptoms, increased positive emotion, decreased negative emotion and stress), whereas the waitlist group significantly increased in depressive mood. Most Phase 2 within-group analyses demonstrated the expected pattern of results (i.e., decreases in PHQ-8 and negative emotion, increases in positive emotion). However, CES-D scores were stable in FC; perceived stress was stable in FC and ODB.

Limitations

This pilot study is not powered to evaluate efficacy.

Conclusion

Positive emotion skills, plus enhancements for web-based, self-guided delivery, warrant additional study in people with elevated depressive symptoms.